Build jansson 1.3 in-tree, if not present on system.

16 files changed, 3622 insertions, 0 deletions

diff --git a/compat/Makefile.am b/compat/Makefile.am
new file mode 100644
index 0000000..77af3c5
--- /dev/null
+++ b/compat/Makefile.am
@@ -0,0 +1,7 @@
+
+if WANT_JANSSON
+SUBDIRS	= jansson
+else
+SUBDIRS	=
+endif
+
diff --git a/compat/jansson/LICENSE b/compat/jansson/LICENSE
new file mode 100644
index 0000000..552b349
--- /dev/null
+++ b/compat/jansson/LICENSE
@@ -0,0 +1,19 @@
+Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/compat/jansson/Makefile.am b/compat/jansson/Makefile.am
new file mode 100644
index 0000000..94a583f
--- /dev/null
+++ b/compat/jansson/Makefile.am
@@ -0,0 +1,18 @@
+
+noinst_LIBRARIES	= libjansson.a
+
+libjansson_a_SOURCES	= \
+			  config.h		\
+			  dump.c		\
+			  hashtable.c		\
+			  hashtable.h		\
+			  jansson.h		\
+			  jansson_private.h	\
+			  load.c		\
+			  strbuffer.c		\
+			  strbuffer.h		\
+			  utf.c			\
+			  utf.h			\
+			  util.h		\
+			  value.c
+
diff --git a/compat/jansson/config.h b/compat/jansson/config.h
new file mode 100644
index 0000000..43858aa
--- /dev/null
+++ b/compat/jansson/config.h
@@ -0,0 +1,73 @@
+/* config.h.  Generated from config.h.in by configure.  */
+/* config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#define HAVE_DLFCN_H 1
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#define HAVE_INTTYPES_H 1
+
+/* Define to 1 if you have the <memory.h> header file. */
+#define HAVE_MEMORY_H 1
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#define HAVE_STDINT_H 1
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#define HAVE_STDLIB_H 1
+
+/* Define to 1 if you have the <strings.h> header file. */
+#define HAVE_STRINGS_H 1
+
+/* Define to 1 if you have the <string.h> header file. */
+#define HAVE_STRING_H 1
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#define HAVE_SYS_STAT_H 1
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#define HAVE_SYS_TYPES_H 1
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#define HAVE_UNISTD_H 1
+
+/* Define to the sub-directory in which libtool stores uninstalled libraries.
+   */
+#define LT_OBJDIR ".libs/"
+
+/* Name of package */
+#define PACKAGE "jansson"
+
+/* Define to the address where bug reports for this package should be sent. */
+#define PACKAGE_BUGREPORT "petri@digip.org"
+
+/* Define to the full name of this package. */
+#define PACKAGE_NAME "jansson"
+
+/* Define to the full name and version of this package. */
+#define PACKAGE_STRING "jansson 1.3"
+
+/* Define to the one symbol short name of this package. */
+#define PACKAGE_TARNAME "jansson"
+
+/* Define to the home page for this package. */
+#define PACKAGE_URL ""
+
+/* Define to the version of this package. */
+#define PACKAGE_VERSION "1.3"
+
+/* Define to 1 if you have the ANSI C header files. */
+#define STDC_HEADERS 1
+
+/* Version number of package */
+#define VERSION "1.3"
+
+/* Define to `__inline__' or `__inline' if that's what the C compiler
+   calls it, or to nothing if 'inline' is not supported under any name.  */
+#ifndef __cplusplus
+/* #undef inline */
+#endif
+
+/* Define to the type of a signed integer type of width exactly 32 bits if
+   such a type exists and the standard includes do not define it. */
+/* #undef int32_t */
diff --git a/compat/jansson/dump.c b/compat/jansson/dump.c
new file mode 100644
index 0000000..dc27fbd
--- /dev/null
+++ b/compat/jansson/dump.c
@@ -0,0 +1,460 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include <jansson.h>
+#include "jansson_private.h"
+#include "strbuffer.h"
+#include "utf.h"
+
+#define MAX_INTEGER_STR_LENGTH  100
+#define MAX_REAL_STR_LENGTH     100
+
+typedef int (*dump_func)(const char *buffer, int size, void *data);
+
+struct string
+{
+    char *buffer;
+    int length;
+    int size;
+};
+
+static int dump_to_strbuffer(const char *buffer, int size, void *data)
+{
+    return strbuffer_append_bytes((strbuffer_t *)data, buffer, size);
+}
+
+static int dump_to_file(const char *buffer, int size, void *data)
+{
+    FILE *dest = (FILE *)data;
+    if(fwrite(buffer, size, 1, dest) != 1)
+        return -1;
+    return 0;
+}
+
+/* 256 spaces (the maximum indentation size) */
+static char whitespace[] = "                                                                                                                                                                                                                                                                ";
+
+static int dump_indent(unsigned long flags, int depth, int space, dump_func dump, void *data)
+{
+    if(JSON_INDENT(flags) > 0)
+    {
+        int i, ws_count = JSON_INDENT(flags);
+
+        if(dump("\n", 1, data))
+            return -1;
+
+        for(i = 0; i < depth; i++)
+        {
+            if(dump(whitespace, ws_count, data))
+                return -1;
+        }
+    }
+    else if(space && !(flags & JSON_COMPACT))
+    {
+        return dump(" ", 1, data);
+    }
+    return 0;
+}
+
+static int dump_string(const char *str, int ascii, dump_func dump, void *data)
+{
+    const char *pos, *end;
+    int32_t codepoint;
+
+    if(dump("\"", 1, data))
+        return -1;
+
+    end = pos = str;
+    while(1)
+    {
+        const char *text;
+        char seq[13];
+        int length;
+
+        while(*end)
+        {
+            end = utf8_iterate(pos, &codepoint);
+            if(!end)
+                return -1;
+
+            /* mandatory escape or control char */
+            if(codepoint == '\\' || codepoint == '"' || codepoint < 0x20)
+                break;
+
+            /* non-ASCII */
+            if(ascii && codepoint > 0x7F)
+                break;
+
+            pos = end;
+        }
+
+        if(pos != str) {
+            if(dump(str, pos - str, data))
+                return -1;
+        }
+
+        if(end == pos)
+            break;
+
+        /* handle \, ", and control codes */
+        length = 2;
+        switch(codepoint)
+        {
+            case '\\': text = "\\\\"; break;
+            case '\"': text = "\\\""; break;
+            case '\b': text = "\\b"; break;
+            case '\f': text = "\\f"; break;
+            case '\n': text = "\\n"; break;
+            case '\r': text = "\\r"; break;
+            case '\t': text = "\\t"; break;
+            default:
+            {
+                /* codepoint is in BMP */
+                if(codepoint < 0x10000)
+                {
+                    sprintf(seq, "\\u%04x", codepoint);
+                    length = 6;
+                }
+
+                /* not in BMP -> construct a UTF-16 surrogate pair */
+                else
+                {
+                    int32_t first, last;
+
+                    codepoint -= 0x10000;
+                    first = 0xD800 | ((codepoint & 0xffc00) >> 10);
+                    last = 0xDC00 | (codepoint & 0x003ff);
+
+                    sprintf(seq, "\\u%04x\\u%04x", first, last);
+                    length = 12;
+                }
+
+                text = seq;
+                break;
+            }
+        }
+
+        if(dump(text, length, data))
+            return -1;
+
+        str = pos = end;
+    }
+
+    return dump("\"", 1, data);
+}
+
+static int object_key_compare_keys(const void *key1, const void *key2)
+{
+    return strcmp((*(const object_key_t **)key1)->key,
+                  (*(const object_key_t **)key2)->key);
+}
+
+static int object_key_compare_serials(const void *key1, const void *key2)
+{
+    return (*(const object_key_t **)key1)->serial -
+           (*(const object_key_t **)key2)->serial;
+}
+
+static int do_dump(const json_t *json, unsigned long flags, int depth,
+                   dump_func dump, void *data)
+{
+    int ascii = flags & JSON_ENSURE_ASCII ? 1 : 0;
+
+    switch(json_typeof(json)) {
+        case JSON_NULL:
+            return dump("null", 4, data);
+
+        case JSON_TRUE:
+            return dump("true", 4, data);
+
+        case JSON_FALSE:
+            return dump("false", 5, data);
+
+        case JSON_INTEGER:
+        {
+            char buffer[MAX_INTEGER_STR_LENGTH];
+            int size;
+
+            size = snprintf(buffer, MAX_INTEGER_STR_LENGTH, "%d", json_integer_value(json));
+            if(size >= MAX_INTEGER_STR_LENGTH)
+                return -1;
+
+            return dump(buffer, size, data);
+        }
+
+        case JSON_REAL:
+        {
+            char buffer[MAX_REAL_STR_LENGTH];
+            int size;
+
+            size = snprintf(buffer, MAX_REAL_STR_LENGTH, "%.17g",
+                            json_real_value(json));
+            if(size >= MAX_REAL_STR_LENGTH)
+                return -1;
+
+            /* Make sure there's a dot or 'e' in the output. Otherwise
+               a real is converted to an integer when decoding */
+            if(strchr(buffer, '.') == NULL &&
+               strchr(buffer, 'e') == NULL)
+            {
+                if(size + 2 >= MAX_REAL_STR_LENGTH) {
+                    /* No space to append ".0" */
+                    return -1;
+                }
+                buffer[size] = '.';
+                buffer[size + 1] = '0';
+                size += 2;
+            }
+
+            return dump(buffer, size, data);
+        }
+
+        case JSON_STRING:
+            return dump_string(json_string_value(json), ascii, dump, data);
+
+        case JSON_ARRAY:
+        {
+            int i;
+            int n;
+            json_array_t *array;
+
+            /* detect circular references */
+            array = json_to_array(json);
+            if(array->visited)
+                goto array_error;
+            array->visited = 1;
+
+            n = json_array_size(json);
+
+            if(dump("[", 1, data))
+                goto array_error;
+            if(n == 0) {
+                array->visited = 0;
+                return dump("]", 1, data);
+            }
+            if(dump_indent(flags, depth + 1, 0, dump, data))
+                goto array_error;
+
+            for(i = 0; i < n; ++i) {
+                if(do_dump(json_array_get(json, i), flags, depth + 1,
+                           dump, data))
+                    goto array_error;
+
+                if(i < n - 1)
+                {
+                    if(dump(",", 1, data) ||
+                       dump_indent(flags, depth + 1, 1, dump, data))
+                        goto array_error;
+                }
+                else
+                {
+                    if(dump_indent(flags, depth, 0, dump, data))
+                        goto array_error;
+                }
+            }
+
+            array->visited = 0;
+            return dump("]", 1, data);
+
+        array_error:
+            array->visited = 0;
+            return -1;
+        }
+
+        case JSON_OBJECT:
+        {
+            json_object_t *object;
+            void *iter;
+            const char *separator;
+            int separator_length;
+
+            if(flags & JSON_COMPACT) {
+                separator = ":";
+                separator_length = 1;
+            }
+            else {
+                separator = ": ";
+                separator_length = 2;
+            }
+
+            /* detect circular references */
+            object = json_to_object(json);
+            if(object->visited)
+                goto object_error;
+            object->visited = 1;
+
+            iter = json_object_iter((json_t *)json);
+
+            if(dump("{", 1, data))
+                goto object_error;
+            if(!iter) {
+                object->visited = 0;
+                return dump("}", 1, data);
+            }
+            if(dump_indent(flags, depth + 1, 0, dump, data))
+                goto object_error;
+
+            if(flags & JSON_SORT_KEYS || flags & JSON_PRESERVE_ORDER)
+            {
+                const object_key_t **keys;
+                unsigned int size;
+                unsigned int i;
+                int (*cmp_func)(const void *, const void *);
+
+                size = json_object_size(json);
+                keys = malloc(size * sizeof(object_key_t *));
+                if(!keys)
+                    goto object_error;
+
+                i = 0;
+                while(iter)
+                {
+                    keys[i] = jsonp_object_iter_fullkey(iter);
+                    iter = json_object_iter_next((json_t *)json, iter);
+                    i++;
+                }
+                assert(i == size);
+
+                if(flags & JSON_SORT_KEYS)
+                    cmp_func = object_key_compare_keys;
+                else
+                    cmp_func = object_key_compare_serials;
+
+                qsort(keys, size, sizeof(object_key_t *), cmp_func);
+
+                for(i = 0; i < size; i++)
+                {
+                    const char *key;
+                    json_t *value;
+
+                    key = keys[i]->key;
+                    value = json_object_get(json, key);
+                    assert(value);
+
+                    dump_string(key, ascii, dump, data);
+                    if(dump(separator, separator_length, data) ||
+                       do_dump(value, flags, depth + 1, dump, data))
+                    {
+                        free(keys);
+                        goto object_error;
+                    }
+
+                    if(i < size - 1)
+                    {
+                        if(dump(",", 1, data) ||
+                           dump_indent(flags, depth + 1, 1, dump, data))
+                        {
+                            free(keys);
+                            goto object_error;
+                        }
+                    }
+                    else
+                    {
+                        if(dump_indent(flags, depth, 0, dump, data))
+                        {
+                            free(keys);
+                            goto object_error;
+                        }
+                    }
+                }
+
+                free(keys);
+            }
+            else
+            {
+                /* Don't sort keys */
+
+                while(iter)
+                {
+                    void *next = json_object_iter_next((json_t *)json, iter);
+
+                    dump_string(json_object_iter_key(iter), ascii, dump, data);
+                    if(dump(separator, separator_length, data) ||
+                       do_dump(json_object_iter_value(iter), flags, depth + 1,
+                               dump, data))
+                        goto object_error;
+
+                    if(next)
+                    {
+                        if(dump(",", 1, data) ||
+                           dump_indent(flags, depth + 1, 1, dump, data))
+                            goto object_error;
+                    }
+                    else
+                    {
+                        if(dump_indent(flags, depth, 0, dump, data))
+                            goto object_error;
+                    }
+
+                    iter = next;
+                }
+            }
+
+            object->visited = 0;
+            return dump("}", 1, data);
+
+        object_error:
+            object->visited = 0;
+            return -1;
+        }
+
+        default:
+            /* not reached */
+            return -1;
+    }
+}
+
+
+char *json_dumps(const json_t *json, unsigned long flags)
+{
+    strbuffer_t strbuff;
+    char *result;
+
+    if(!json_is_array(json) && !json_is_object(json))
+        return NULL;
+
+    if(strbuffer_init(&strbuff))
+        return NULL;
+
+    if(do_dump(json, flags, 0, dump_to_strbuffer, (void *)&strbuff)) {
+        strbuffer_close(&strbuff);
+        return NULL;
+    }
+
+    result = strdup(strbuffer_value(&strbuff));
+    strbuffer_close(&strbuff);
+
+    return result;
+}
+
+int json_dumpf(const json_t *json, FILE *output, unsigned long flags)
+{
+    if(!json_is_array(json) && !json_is_object(json))
+        return -1;
+
+    return do_dump(json, flags, 0, dump_to_file, (void *)output);
+}
+
+int json_dump_file(const json_t *json, const char *path, unsigned long flags)
+{
+    int result;
+
+    FILE *output = fopen(path, "w");
+    if(!output)
+        return -1;
+
+    result = json_dumpf(json, output, flags);
+
+    fclose(output);
+    return result;
+}
diff --git a/compat/jansson/hashtable.c b/compat/jansson/hashtable.c
new file mode 100644
index 0000000..a312047
--- /dev/null
+++ b/compat/jansson/hashtable.c
@@ -0,0 +1,375 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <config.h>
+
+#include <stdlib.h>
+#include "hashtable.h"
+
+typedef struct hashtable_list list_t;
+typedef struct hashtable_pair pair_t;
+typedef struct hashtable_bucket bucket_t;
+
+#define container_of(ptr_, type_, member_)                      \
+    ((type_ *)((char *)ptr_ - (size_t)&((type_ *)0)->member_))
+
+#define list_to_pair(list_)  container_of(list_, pair_t, list)
+
+static inline void list_init(list_t *list)
+{
+    list->next = list;
+    list->prev = list;
+}
+
+static inline void list_insert(list_t *list, list_t *node)
+{
+    node->next = list;
+    node->prev = list->prev;
+    list->prev->next = node;
+    list->prev = node;
+}
+
+static inline void list_remove(list_t *list)
+{
+    list->prev->next = list->next;
+    list->next->prev = list->prev;
+}
+
+static inline int bucket_is_empty(hashtable_t *hashtable, bucket_t *bucket)
+{
+    return bucket->first == &hashtable->list && bucket->first == bucket->last;
+}
+
+static void insert_to_bucket(hashtable_t *hashtable, bucket_t *bucket,
+                             list_t *list)
+{
+    if(bucket_is_empty(hashtable, bucket))
+    {
+        list_insert(&hashtable->list, list);
+        bucket->first = bucket->last = list;
+    }
+    else
+    {
+        list_insert(bucket->first, list);
+        bucket->first = list;
+    }
+}
+
+static unsigned int primes[] = {
+    5, 13, 23, 53, 97, 193, 389, 769, 1543, 3079, 6151, 12289, 24593,
+    49157, 98317, 196613, 393241, 786433, 1572869, 3145739, 6291469,
+    12582917, 25165843, 50331653, 100663319, 201326611, 402653189,
+    805306457, 1610612741
+};
+static const unsigned int num_primes = sizeof(primes) / sizeof(unsigned int);
+
+static inline unsigned int num_buckets(hashtable_t *hashtable)
+{
+    return primes[hashtable->num_buckets];
+}
+
+
+static pair_t *hashtable_find_pair(hashtable_t *hashtable, bucket_t *bucket,
+                                   const void *key, unsigned int hash)
+{
+    list_t *list;
+    pair_t *pair;
+
+    if(bucket_is_empty(hashtable, bucket))
+        return NULL;
+
+    list = bucket->first;
+    while(1)
+    {
+        pair = list_to_pair(list);
+        if(pair->hash == hash && hashtable->cmp_keys(pair->key, key))
+            return pair;
+
+        if(list == bucket->last)
+            break;
+
+        list = list->next;
+    }
+
+    return NULL;
+}
+
+/* returns 0 on success, -1 if key was not found */
+static int hashtable_do_del(hashtable_t *hashtable,
+                            const void *key, unsigned int hash)
+{
+    pair_t *pair;
+    bucket_t *bucket;
+    unsigned int index;
+
+    index = hash % num_buckets(hashtable);
+    bucket = &hashtable->buckets[index];
+
+    pair = hashtable_find_pair(hashtable, bucket, key, hash);
+    if(!pair)
+        return -1;
+
+    if(&pair->list == bucket->first && &pair->list == bucket->last)
+        bucket->first = bucket->last = &hashtable->list;
+
+    else if(&pair->list == bucket->first)
+        bucket->first = pair->list.next;
+
+    else if(&pair->list == bucket->last)
+        bucket->last = pair->list.prev;
+
+    list_remove(&pair->list);
+
+    if(hashtable->free_key)
+        hashtable->free_key(pair->key);
+    if(hashtable->free_value)
+        hashtable->free_value(pair->value);
+
+    free(pair);
+    hashtable->size--;
+
+    return 0;
+}
+
+static void hashtable_do_clear(hashtable_t *hashtable)
+{
+    list_t *list, *next;
+    pair_t *pair;
+
+    for(list = hashtable->list.next; list != &hashtable->list; list = next)
+    {
+        next = list->next;
+        pair = list_to_pair(list);
+        if(hashtable->free_key)
+            hashtable->free_key(pair->key);
+        if(hashtable->free_value)
+            hashtable->free_value(pair->value);
+        free(pair);
+    }
+}
+
+static int hashtable_do_rehash(hashtable_t *hashtable)
+{
+    list_t *list, *next;
+    pair_t *pair;
+    unsigned int i, index, new_size;
+
+    free(hashtable->buckets);
+
+    hashtable->num_buckets++;
+    new_size = num_buckets(hashtable);
+
+    hashtable->buckets = malloc(new_size * sizeof(bucket_t));
+    if(!hashtable->buckets)
+        return -1;
+
+    for(i = 0; i < num_buckets(hashtable); i++)
+    {
+        hashtable->buckets[i].first = hashtable->buckets[i].last =
+            &hashtable->list;
+    }
+
+    list = hashtable->list.next;
+    list_init(&hashtable->list);
+
+    for(; list != &hashtable->list; list = next) {
+        next = list->next;
+        pair = list_to_pair(list);
+        index = pair->hash % new_size;
+        insert_to_bucket(hashtable, &hashtable->buckets[index], &pair->list);
+    }
+
+    return 0;
+}
+
+
+hashtable_t *hashtable_create(key_hash_fn hash_key, key_cmp_fn cmp_keys,
+                              free_fn free_key, free_fn free_value)
+{
+    hashtable_t *hashtable = malloc(sizeof(hashtable_t));
+    if(!hashtable)
+        return NULL;
+
+    if(hashtable_init(hashtable, hash_key, cmp_keys, free_key, free_value))
+    {
+        free(hashtable);
+        return NULL;
+    }
+
+    return hashtable;
+}
+
+void hashtable_destroy(hashtable_t *hashtable)
+{
+    hashtable_close(hashtable);
+    free(hashtable);
+}
+
+int hashtable_init(hashtable_t *hashtable,
+                   key_hash_fn hash_key, key_cmp_fn cmp_keys,
+                   free_fn free_key, free_fn free_value)
+{
+    unsigned int i;
+
+    hashtable->size = 0;
+    hashtable->num_buckets = 0;  /* index to primes[] */
+    hashtable->buckets = malloc(num_buckets(hashtable) * sizeof(bucket_t));
+    if(!hashtable->buckets)
+        return -1;
+
+    list_init(&hashtable->list);
+
+    hashtable->hash_key = hash_key;
+    hashtable->cmp_keys = cmp_keys;
+    hashtable->free_key = free_key;
+    hashtable->free_value = free_value;
+
+    for(i = 0; i < num_buckets(hashtable); i++)
+    {
+        hashtable->buckets[i].first = hashtable->buckets[i].last =
+            &hashtable->list;
+    }
+
+    return 0;
+}
+
+void hashtable_close(hashtable_t *hashtable)
+{
+    hashtable_do_clear(hashtable);
+    free(hashtable->buckets);
+}
+
+int hashtable_set(hashtable_t *hashtable, void *key, void *value)
+{
+    pair_t *pair;
+    bucket_t *bucket;
+    unsigned int hash, index;
+
+    /* rehash if the load ratio exceeds 1 */
+    if(hashtable->size >= num_buckets(hashtable))
+        if(hashtable_do_rehash(hashtable))
+            return -1;
+
+    hash = hashtable->hash_key(key);
+    index = hash % num_buckets(hashtable);
+    bucket = &hashtable->buckets[index];
+    pair = hashtable_find_pair(hashtable, bucket, key, hash);
+
+    if(pair)
+    {
+        if(hashtable->free_key)
+            hashtable->free_key(key);
+        if(hashtable->free_value)
+            hashtable->free_value(pair->value);
+        pair->value = value;
+    }
+    else
+    {
+        pair = malloc(sizeof(pair_t));
+        if(!pair)
+            return -1;
+
+        pair->key = key;
+        pair->value = value;
+        pair->hash = hash;
+        list_init(&pair->list);
+
+        insert_to_bucket(hashtable, bucket, &pair->list);
+
+        hashtable->size++;
+    }
+    return 0;
+}
+
+void *hashtable_get(hashtable_t *hashtable, const void *key)
+{
+    pair_t *pair;
+    unsigned int hash;
+    bucket_t *bucket;
+
+    hash = hashtable->hash_key(key);
+    bucket = &hashtable->buckets[hash % num_buckets(hashtable)];
+
+    pair = hashtable_find_pair(hashtable, bucket, key, hash);
+    if(!pair)
+        return NULL;
+
+    return pair->value;
+}
+
+int hashtable_del(hashtable_t *hashtable, const void *key)
+{
+    unsigned int hash = hashtable->hash_key(key);
+    return hashtable_do_del(hashtable, key, hash);
+}
+
+void hashtable_clear(hashtable_t *hashtable)
+{
+    unsigned int i;
+
+    hashtable_do_clear(hashtable);
+
+    for(i = 0; i < num_buckets(hashtable); i++)
+    {
+        hashtable->buckets[i].first = hashtable->buckets[i].last =
+            &hashtable->list;
+    }
+
+    list_init(&hashtable->list);
+    hashtable->size = 0;
+}
+
+void *hashtable_iter(hashtable_t *hashtable)
+{
+    return hashtable_iter_next(hashtable, &hashtable->list);
+}
+
+void *hashtable_iter_at(hashtable_t *hashtable, const void *key)
+{
+    pair_t *pair;
+    unsigned int hash;
+    bucket_t *bucket;
+
+    hash = hashtable->hash_key(key);
+    bucket = &hashtable->buckets[hash % num_buckets(hashtable)];
+
+    pair = hashtable_find_pair(hashtable, bucket, key, hash);
+    if(!pair)
+        return NULL;
+
+    return &pair->list;
+}
+
+void *hashtable_iter_next(hashtable_t *hashtable, void *iter)
+{
+    list_t *list = (list_t *)iter;
+    if(list->next == &hashtable->list)
+        return NULL;
+    return list->next;
+}
+
+void *hashtable_iter_key(void *iter)
+{
+    pair_t *pair = list_to_pair((list_t *)iter);
+    return pair->key;
+}
+
+void *hashtable_iter_value(void *iter)
+{
+    pair_t *pair = list_to_pair((list_t *)iter);
+    return pair->value;
+}
+
+void hashtable_iter_set(hashtable_t *hashtable, void *iter, void *value)
+{
+    pair_t *pair = list_to_pair((list_t *)iter);
+
+    if(hashtable->free_value)
+        hashtable->free_value(pair->value);
+
+    pair->value = value;
+}
diff --git a/compat/jansson/hashtable.h b/compat/jansson/hashtable.h
new file mode 100644
index 0000000..f03a769
--- /dev/null
+++ b/compat/jansson/hashtable.h
@@ -0,0 +1,207 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef HASHTABLE_H
+#define HASHTABLE_H
+
+typedef unsigned int (*key_hash_fn)(const void *key);
+typedef int (*key_cmp_fn)(const void *key1, const void *key2);
+typedef void (*free_fn)(void *key);
+
+struct hashtable_list {
+    struct hashtable_list *prev;
+    struct hashtable_list *next;
+};
+
+struct hashtable_pair {
+    void *key;
+    void *value;
+    unsigned int hash;
+    struct hashtable_list list;
+};
+
+struct hashtable_bucket {
+    struct hashtable_list *first;
+    struct hashtable_list *last;
+};
+
+typedef struct hashtable {
+    unsigned int size;
+    struct hashtable_bucket *buckets;
+    unsigned int num_buckets;  /* index to primes[] */
+    struct hashtable_list list;
+
+    key_hash_fn hash_key;
+    key_cmp_fn cmp_keys;  /* returns non-zero for equal keys */
+    free_fn free_key;
+    free_fn free_value;
+} hashtable_t;
+
+/**
+ * hashtable_create - Create a hashtable object
+ *
+ * @hash_key: The key hashing function
+ * @cmp_keys: The key compare function. Returns non-zero for equal and
+ *     zero for unequal unequal keys
+ * @free_key: If non-NULL, called for a key that is no longer referenced.
+ * @free_value: If non-NULL, called for a value that is no longer referenced.
+ *
+ * Returns a new hashtable object that should be freed with
+ * hashtable_destroy when it's no longer used, or NULL on failure (out
+ * of memory).
+ */
+hashtable_t *hashtable_create(key_hash_fn hash_key, key_cmp_fn cmp_keys,
+                              free_fn free_key, free_fn free_value);
+
+/**
+ * hashtable_destroy - Destroy a hashtable object
+ *
+ * @hashtable: The hashtable
+ *
+ * Destroys a hashtable created with hashtable_create().
+ */
+void hashtable_destroy(hashtable_t *hashtable);
+
+/**
+ * hashtable_init - Initialize a hashtable object
+ *
+ * @hashtable: The (statically allocated) hashtable object
+ * @hash_key: The key hashing function
+ * @cmp_keys: The key compare function. Returns non-zero for equal and
+ *     zero for unequal unequal keys
+ * @free_key: If non-NULL, called for a key that is no longer referenced.
+ * @free_value: If non-NULL, called for a value that is no longer referenced.
+ *
+ * Initializes a statically allocated hashtable object. The object
+ * should be cleared with hashtable_close when it's no longer used.
+ *
+ * Returns 0 on success, -1 on error (out of memory).
+ */
+int hashtable_init(hashtable_t *hashtable,
+                   key_hash_fn hash_key, key_cmp_fn cmp_keys,
+                   free_fn free_key, free_fn free_value);
+
+/**
+ * hashtable_close - Release all resources used by a hashtable object
+ *
+ * @hashtable: The hashtable
+ *
+ * Destroys a statically allocated hashtable object.
+ */
+void hashtable_close(hashtable_t *hashtable);
+
+/**
+ * hashtable_set - Add/modify value in hashtable
+ *
+ * @hashtable: The hashtable object
+ * @key: The key
+ * @value: The value
+ *
+ * If a value with the given key already exists, its value is replaced
+ * with the new value.
+ *
+ * Key and value are "stealed" in the sense that hashtable frees them
+ * automatically when they are no longer used. The freeing is
+ * accomplished by calling free_key and free_value functions that were
+ * supplied to hashtable_new. In case one or both of the free
+ * functions is NULL, the corresponding item is not "stealed".
+ *
+ * Returns 0 on success, -1 on failure (out of memory).
+ */
+int hashtable_set(hashtable_t *hashtable, void *key, void *value);
+
+/**
+ * hashtable_get - Get a value associated with a key
+ *
+ * @hashtable: The hashtable object
+ * @key: The key
+ *
+ * Returns value if it is found, or NULL otherwise.
+ */
+void *hashtable_get(hashtable_t *hashtable, const void *key);
+
+/**
+ * hashtable_del - Remove a value from the hashtable
+ *
+ * @hashtable: The hashtable object
+ * @key: The key
+ *
+ * Returns 0 on success, or -1 if the key was not found.
+ */
+int hashtable_del(hashtable_t *hashtable, const void *key);
+
+/**
+ * hashtable_clear - Clear hashtable
+ *
+ * @hashtable: The hashtable object
+ *
+ * Removes all items from the hashtable.
+ */
+void hashtable_clear(hashtable_t *hashtable);
+
+/**
+ * hashtable_iter - Iterate over hashtable
+ *
+ * @hashtable: The hashtable object
+ *
+ * Returns an opaque iterator to the first element in the hashtable.
+ * The iterator should be passed to hashtable_iter_* functions.
+ * The hashtable items are not iterated over in any particular order.
+ *
+ * There's no need to free the iterator in any way. The iterator is
+ * valid as long as the item that is referenced by the iterator is not
+ * deleted. Other values may be added or deleted. In particular,
+ * hashtable_iter_next() may be called on an iterator, and after that
+ * the key/value pair pointed by the old iterator may be deleted.
+ */
+void *hashtable_iter(hashtable_t *hashtable);
+
+/**
+ * hashtable_iter_at - Return an iterator at a specific key
+ *
+ * @hashtable: The hashtable object
+ * @key: The key that the iterator should point to
+ *
+ * Like hashtable_iter() but returns an iterator pointing to a
+ * specific key.
+ */
+void *hashtable_iter_at(hashtable_t *hashtable, const void *key);
+
+/**
+ * hashtable_iter_next - Advance an iterator
+ *
+ * @hashtable: The hashtable object
+ * @iter: The iterator
+ *
+ * Returns a new iterator pointing to the next element in the
+ * hashtable or NULL if the whole hastable has been iterated over.
+ */
+void *hashtable_iter_next(hashtable_t *hashtable, void *iter);
+
+/**
+ * hashtable_iter_key - Retrieve the key pointed by an iterator
+ *
+ * @iter: The iterator
+ */
+void *hashtable_iter_key(void *iter);
+
+/**
+ * hashtable_iter_value - Retrieve the value pointed by an iterator
+ *
+ * @iter: The iterator
+ */
+void *hashtable_iter_value(void *iter);
+
+/**
+ * hashtable_iter_set - Set the value pointed by an iterator
+ *
+ * @iter: The iterator
+ * @value: The value to set
+ */
+void hashtable_iter_set(hashtable_t *hashtable, void *iter, void *value);
+
+#endif
diff --git a/compat/jansson/jansson.h b/compat/jansson/jansson.h
new file mode 100644
index 0000000..4c526fe
--- /dev/null
+++ b/compat/jansson/jansson.h
@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef JANSSON_H
+#define JANSSON_H
+
+#include <stdio.h>
+
+#ifndef __cplusplus
+#define JSON_INLINE inline
+#else
+#define JSON_INLINE inline
+extern "C" {
+#endif
+
+/* types */
+
+typedef enum {
+    JSON_OBJECT,
+    JSON_ARRAY,
+    JSON_STRING,
+    JSON_INTEGER,
+    JSON_REAL,
+    JSON_TRUE,
+    JSON_FALSE,
+    JSON_NULL
+} json_type;
+
+typedef struct {
+    json_type type;
+    unsigned long refcount;
+} json_t;
+
+#define json_typeof(json)      ((json)->type)
+#define json_is_object(json)   (json && json_typeof(json) == JSON_OBJECT)
+#define json_is_array(json)    (json && json_typeof(json) == JSON_ARRAY)
+#define json_is_string(json)   (json && json_typeof(json) == JSON_STRING)
+#define json_is_integer(json)  (json && json_typeof(json) == JSON_INTEGER)
+#define json_is_real(json)     (json && json_typeof(json) == JSON_REAL)
+#define json_is_number(json)   (json_is_integer(json) || json_is_real(json))
+#define json_is_true(json)     (json && json_typeof(json) == JSON_TRUE)
+#define json_is_false(json)    (json && json_typeof(json) == JSON_FALSE)
+#define json_is_boolean(json)  (json_is_true(json) || json_is_false(json))
+#define json_is_null(json)     (json && json_typeof(json) == JSON_NULL)
+
+/* construction, destruction, reference counting */
+
+json_t *json_object(void);
+json_t *json_array(void);
+json_t *json_string(const char *value);
+json_t *json_string_nocheck(const char *value);
+json_t *json_integer(int value);
+json_t *json_real(double value);
+json_t *json_true(void);
+json_t *json_false(void);
+json_t *json_null(void);
+
+static JSON_INLINE
+json_t *json_incref(json_t *json)
+{
+    if(json && json->refcount != (unsigned int)-1)
+        ++json->refcount;
+    return json;
+}
+
+/* do not call json_delete directly */
+void json_delete(json_t *json);
+
+static JSON_INLINE
+void json_decref(json_t *json)
+{
+    if(json && json->refcount != (unsigned int)-1 && --json->refcount == 0)
+        json_delete(json);
+}
+
+
+/* getters, setters, manipulation */
+
+unsigned int json_object_size(const json_t *object);
+json_t *json_object_get(const json_t *object, const char *key);
+int json_object_set_new(json_t *object, const char *key, json_t *value);
+int json_object_set_new_nocheck(json_t *object, const char *key, json_t *value);
+int json_object_del(json_t *object, const char *key);
+int json_object_clear(json_t *object);
+int json_object_update(json_t *object, json_t *other);
+void *json_object_iter(json_t *object);
+void *json_object_iter_at(json_t *object, const char *key);
+void *json_object_iter_next(json_t *object, void *iter);
+const char *json_object_iter_key(void *iter);
+json_t *json_object_iter_value(void *iter);
+int json_object_iter_set_new(json_t *object, void *iter, json_t *value);
+
+static JSON_INLINE
+int json_object_set(json_t *object, const char *key, json_t *value)
+{
+    return json_object_set_new(object, key, json_incref(value));
+}
+
+static JSON_INLINE
+int json_object_set_nocheck(json_t *object, const char *key, json_t *value)
+{
+    return json_object_set_new_nocheck(object, key, json_incref(value));
+}
+
+static inline
+int json_object_iter_set(json_t *object, void *iter, json_t *value)
+{
+    return json_object_iter_set_new(object, iter, json_incref(value));
+}
+
+unsigned int json_array_size(const json_t *array);
+json_t *json_array_get(const json_t *array, unsigned int index);
+int json_array_set_new(json_t *array, unsigned int index, json_t *value);
+int json_array_append_new(json_t *array, json_t *value);
+int json_array_insert_new(json_t *array, unsigned int index, json_t *value);
+int json_array_remove(json_t *array, unsigned int index);
+int json_array_clear(json_t *array);
+int json_array_extend(json_t *array, json_t *other);
+
+static JSON_INLINE
+int json_array_set(json_t *array, unsigned int index, json_t *value)
+{
+    return json_array_set_new(array, index, json_incref(value));
+}
+
+static JSON_INLINE
+int json_array_append(json_t *array, json_t *value)
+{
+    return json_array_append_new(array, json_incref(value));
+}
+
+static JSON_INLINE
+int json_array_insert(json_t *array, unsigned int index, json_t *value)
+{
+    return json_array_insert_new(array, index, json_incref(value));
+}
+
+const char *json_string_value(const json_t *string);
+int json_integer_value(const json_t *integer);
+double json_real_value(const json_t *real);
+double json_number_value(const json_t *json);
+
+int json_string_set(json_t *string, const char *value);
+int json_string_set_nocheck(json_t *string, const char *value);
+int json_integer_set(json_t *integer, int value);
+int json_real_set(json_t *real, double value);
+
+
+/* equality */
+
+int json_equal(json_t *value1, json_t *value2);
+
+
+/* copying */
+
+json_t *json_copy(json_t *value);
+json_t *json_deep_copy(json_t *value);
+
+
+/* loading, printing */
+
+#define JSON_ERROR_TEXT_LENGTH  160
+
+typedef struct {
+    char text[JSON_ERROR_TEXT_LENGTH];
+    int line;
+} json_error_t;
+
+json_t *json_loads(const char *input, json_error_t *error);
+json_t *json_loadf(FILE *input, json_error_t *error);
+json_t *json_load_file(const char *path, json_error_t *error);
+
+#define JSON_INDENT(n)      (n & 0xFF)
+#define JSON_COMPACT        0x100
+#define JSON_ENSURE_ASCII   0x200
+#define JSON_SORT_KEYS      0x400
+#define JSON_PRESERVE_ORDER 0x800
+
+char *json_dumps(const json_t *json, unsigned long flags);
+int json_dumpf(const json_t *json, FILE *output, unsigned long flags);
+int json_dump_file(const json_t *json, const char *path, unsigned long flags);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/compat/jansson/jansson_private.h b/compat/jansson/jansson_private.h
new file mode 100644
index 0000000..4490702
--- /dev/null
+++ b/compat/jansson/jansson_private.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef JANSSON_PRIVATE_H
+#define JANSSON_PRIVATE_H
+
+#include "jansson.h"
+#include "hashtable.h"
+
+#define container_of(ptr_, type_, member_)  \
+    ((type_ *)((char *)ptr_ - (size_t)&((type_ *)0)->member_))
+
+typedef struct {
+    json_t json;
+    hashtable_t hashtable;
+    unsigned long serial;
+    int visited;
+} json_object_t;
+
+typedef struct {
+    json_t json;
+    unsigned int size;
+    unsigned int entries;
+    json_t **table;
+    int visited;
+} json_array_t;
+
+typedef struct {
+    json_t json;
+    char *value;
+} json_string_t;
+
+typedef struct {
+    json_t json;
+    double value;
+} json_real_t;
+
+typedef struct {
+    json_t json;
+    int value;
+} json_integer_t;
+
+#define json_to_object(json_)  container_of(json_, json_object_t, json)
+#define json_to_array(json_)   container_of(json_, json_array_t, json)
+#define json_to_string(json_)  container_of(json_, json_string_t, json)
+#define json_to_real(json_)   container_of(json_, json_real_t, json)
+#define json_to_integer(json_) container_of(json_, json_integer_t, json)
+
+typedef struct {
+    unsigned long serial;
+    char key[];
+} object_key_t;
+
+const object_key_t *jsonp_object_iter_fullkey(void *iter);
+
+#endif
diff --git a/compat/jansson/load.c b/compat/jansson/load.c
new file mode 100644
index 0000000..d49a4da
--- /dev/null
+++ b/compat/jansson/load.c
@@ -0,0 +1,879 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#define _GNU_SOURCE
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <assert.h>
+
+#include <jansson.h>
+#include "jansson_private.h"
+#include "strbuffer.h"
+#include "utf.h"
+
+#define TOKEN_INVALID         -1
+#define TOKEN_EOF              0
+#define TOKEN_STRING         256
+#define TOKEN_INTEGER        257
+#define TOKEN_REAL           258
+#define TOKEN_TRUE           259
+#define TOKEN_FALSE          260
+#define TOKEN_NULL           261
+
+/* read one byte from stream, return EOF on end of file */
+typedef int (*get_func)(void *data);
+
+/* return non-zero if end of file has been reached */
+typedef int (*eof_func)(void *data);
+
+typedef struct {
+    get_func get;
+    eof_func eof;
+    void *data;
+    int stream_pos;
+    char buffer[5];
+    int buffer_pos;
+} stream_t;
+
+
+typedef struct {
+    stream_t stream;
+    strbuffer_t saved_text;
+    int token;
+    int line, column;
+    union {
+        char *string;
+        int integer;
+        double real;
+    } value;
+} lex_t;
+
+
+/*** error reporting ***/
+
+static void error_init(json_error_t *error)
+{
+    if(error)
+    {
+        error->text[0] = '\0';
+        error->line = -1;
+    }
+}
+
+static void error_set(json_error_t *error, const lex_t *lex,
+                      const char *msg, ...)
+{
+    va_list ap;
+    char text[JSON_ERROR_TEXT_LENGTH];
+
+    if(!error || error->text[0] != '\0') {
+        /* error already set */
+        return;
+    }
+
+    va_start(ap, msg);
+    vsnprintf(text, JSON_ERROR_TEXT_LENGTH, msg, ap);
+    va_end(ap);
+
+    if(lex)
+    {
+        const char *saved_text = strbuffer_value(&lex->saved_text);
+        error->line = lex->line;
+        if(saved_text && saved_text[0])
+        {
+            if(lex->saved_text.length <= 20) {
+                snprintf(error->text, JSON_ERROR_TEXT_LENGTH,
+                         "%s near '%s'", text, saved_text);
+            }
+            else
+                snprintf(error->text, JSON_ERROR_TEXT_LENGTH, "%s", text);
+        }
+        else
+        {
+            snprintf(error->text, JSON_ERROR_TEXT_LENGTH,
+                     "%s near end of file", text);
+        }
+    }
+    else
+    {
+        error->line = -1;
+        snprintf(error->text, JSON_ERROR_TEXT_LENGTH, "%s", text);
+    }
+}
+
+
+/*** lexical analyzer ***/
+
+static void
+stream_init(stream_t *stream, get_func get, eof_func eof, void *data)
+{
+    stream->get = get;
+    stream->eof = eof;
+    stream->data = data;
+    stream->stream_pos = 0;
+    stream->buffer[0] = '\0';
+    stream->buffer_pos = 0;
+}
+
+static char stream_get(stream_t *stream, json_error_t *error)
+{
+    char c;
+
+    if(!stream->buffer[stream->buffer_pos])
+    {
+        stream->buffer[0] = stream->get(stream->data);
+        stream->buffer_pos = 0;
+
+        c = stream->buffer[0];
+
+        if((unsigned char)c >= 0x80 && c != (char)EOF)
+        {
+            /* multi-byte UTF-8 sequence */
+            int i, count;
+
+            count = utf8_check_first(c);
+            if(!count)
+                goto out;
+
+            assert(count >= 2);
+
+            for(i = 1; i < count; i++)
+                stream->buffer[i] = stream->get(stream->data);
+
+            if(!utf8_check_full(stream->buffer, count, NULL))
+                goto out;
+
+            stream->stream_pos += count;
+            stream->buffer[count] = '\0';
+        }
+        else {
+            stream->buffer[1] = '\0';
+            stream->stream_pos++;
+        }
+    }
+
+    return stream->buffer[stream->buffer_pos++];
+
+out:
+    error_set(error, NULL, "unable to decode byte 0x%x at position %d",
+              (unsigned char)c, stream->stream_pos);
+
+    stream->buffer[0] = EOF;
+    stream->buffer[1] = '\0';
+    stream->buffer_pos = 1;
+
+    return EOF;
+}
+
+static void stream_unget(stream_t *stream, char c)
+{
+    assert(stream->buffer_pos > 0);
+    stream->buffer_pos--;
+    assert(stream->buffer[stream->buffer_pos] == c);
+}
+
+
+static int lex_get(lex_t *lex, json_error_t *error)
+{
+    return stream_get(&lex->stream, error);
+}
+
+static int lex_eof(lex_t *lex)
+{
+    return lex->stream.eof(lex->stream.data);
+}
+
+static void lex_save(lex_t *lex, char c)
+{
+    strbuffer_append_byte(&lex->saved_text, c);
+}
+
+static int lex_get_save(lex_t *lex, json_error_t *error)
+{
+    char c = stream_get(&lex->stream, error);
+    lex_save(lex, c);
+    return c;
+}
+
+static void lex_unget_unsave(lex_t *lex, char c)
+{
+    char d;
+    stream_unget(&lex->stream, c);
+    d = strbuffer_pop(&lex->saved_text);
+    assert(c == d);
+}
+
+static void lex_save_cached(lex_t *lex)
+{
+    while(lex->stream.buffer[lex->stream.buffer_pos] != '\0')
+    {
+        lex_save(lex, lex->stream.buffer[lex->stream.buffer_pos]);
+        lex->stream.buffer_pos++;
+    }
+}
+
+/* assumes that str points to 'u' plus at least 4 valid hex digits */
+static int32_t decode_unicode_escape(const char *str)
+{
+    int i;
+    int32_t value = 0;
+
+    assert(str[0] == 'u');
+
+    for(i = 1; i <= 4; i++) {
+        char c = str[i];
+        value <<= 4;
+        if(isdigit(c))
+            value += c - '0';
+        else if(islower(c))
+            value += c - 'a' + 10;
+        else if(isupper(c))
+            value += c - 'A' + 10;
+        else
+            assert(0);
+    }
+
+    return value;
+}
+
+static void lex_scan_string(lex_t *lex, json_error_t *error)
+{
+    char c;
+    const char *p;
+    char *t;
+    int i;
+
+    lex->value.string = NULL;
+    lex->token = TOKEN_INVALID;
+
+    c = lex_get_save(lex, error);
+
+    while(c != '"') {
+        if(c == (char)EOF) {
+            lex_unget_unsave(lex, c);
+            if(lex_eof(lex))
+                error_set(error, lex, "premature end of input");
+            goto out;
+        }
+
+        else if((unsigned char)c <= 0x1F) {
+            /* control character */
+            lex_unget_unsave(lex, c);
+            if(c == '\n')
+                error_set(error, lex, "unexpected newline", c);
+            else
+                error_set(error, lex, "control character 0x%x", c);
+            goto out;
+        }
+
+        else if(c == '\\') {
+            c = lex_get_save(lex, error);
+            if(c == 'u') {
+                c = lex_get_save(lex, error);
+                for(i = 0; i < 4; i++) {
+                    if(!isxdigit(c)) {
+                        lex_unget_unsave(lex, c);
+                        error_set(error, lex, "invalid escape");
+                        goto out;
+                    }
+                    c = lex_get_save(lex, error);
+                }
+            }
+            else if(c == '"' || c == '\\' || c == '/' || c == 'b' ||
+                    c == 'f' || c == 'n' || c == 'r' || c == 't')
+                c = lex_get_save(lex, error);
+            else {
+                lex_unget_unsave(lex, c);
+                error_set(error, lex, "invalid escape");
+                goto out;
+            }
+        }
+        else
+            c = lex_get_save(lex, error);
+    }
+
+    /* the actual value is at most of the same length as the source
+       string, because:
+         - shortcut escapes (e.g. "\t") (length 2) are converted to 1 byte
+         - a single \uXXXX escape (length 6) is converted to at most 3 bytes
+         - two \uXXXX escapes (length 12) forming an UTF-16 surrogate pair
+           are converted to 4 bytes
+    */
+    lex->value.string = malloc(lex->saved_text.length + 1);
+    if(!lex->value.string) {
+        /* this is not very nice, since TOKEN_INVALID is returned */
+        goto out;
+    }
+
+    /* the target */
+    t = lex->value.string;
+
+    /* + 1 to skip the " */
+    p = strbuffer_value(&lex->saved_text) + 1;
+
+    while(*p != '"') {
+        if(*p == '\\') {
+            p++;
+            if(*p == 'u') {
+                char buffer[4];
+                int length;
+                int32_t value;
+
+                value = decode_unicode_escape(p);
+                p += 5;
+
+                if(0xD800 <= value && value <= 0xDBFF) {
+                    /* surrogate pair */
+                    if(*p == '\\' && *(p + 1) == 'u') {
+                        int32_t value2 = decode_unicode_escape(++p);
+                        p += 5;
+
+                        if(0xDC00 <= value2 && value2 <= 0xDFFF) {
+                            /* valid second surrogate */
+                            value =
+                                ((value - 0xD800) << 10) +
+                                (value2 - 0xDC00) +
+                                0x10000;
+                        }
+                        else {
+                            /* invalid second surrogate */
+                            error_set(error, lex,
+                                      "invalid Unicode '\\u%04X\\u%04X'",
+                                      value, value2);
+                            goto out;
+                        }
+                    }
+                    else {
+                        /* no second surrogate */
+                        error_set(error, lex, "invalid Unicode '\\u%04X'",
+                                  value);
+                        goto out;
+                    }
+                }
+                else if(0xDC00 <= value && value <= 0xDFFF) {
+                    error_set(error, lex, "invalid Unicode '\\u%04X'", value);
+                    goto out;
+                }
+                else if(value == 0)
+                {
+                    error_set(error, lex, "\\u0000 is not allowed");
+                    goto out;
+                }
+
+                if(utf8_encode(value, buffer, &length))
+                    assert(0);
+
+                memcpy(t, buffer, length);
+                t += length;
+            }
+            else {
+                switch(*p) {
+                    case '"': case '\\': case '/':
+                        *t = *p; break;
+                    case 'b': *t = '\b'; break;
+                    case 'f': *t = '\f'; break;
+                    case 'n': *t = '\n'; break;
+                    case 'r': *t = '\r'; break;
+                    case 't': *t = '\t'; break;
+                    default: assert(0);
+                }
+                t++;
+                p++;
+            }
+        }
+        else
+            *(t++) = *(p++);
+    }
+    *t = '\0';
+    lex->token = TOKEN_STRING;
+    return;
+
+out:
+    free(lex->value.string);
+}
+
+static int lex_scan_number(lex_t *lex, char c, json_error_t *error)
+{
+    const char *saved_text;
+    char *end;
+    double value;
+
+    lex->token = TOKEN_INVALID;
+
+    if(c == '-')
+        c = lex_get_save(lex, error);
+
+    if(c == '0') {
+        c = lex_get_save(lex, error);
+        if(isdigit(c)) {
+            lex_unget_unsave(lex, c);
+            goto out;
+        }
+    }
+    else if(isdigit(c)) {
+        c = lex_get_save(lex, error);
+        while(isdigit(c))
+            c = lex_get_save(lex, error);
+    }
+    else {
+      lex_unget_unsave(lex, c);
+      goto out;
+    }
+
+    if(c != '.' && c != 'E' && c != 'e') {
+        long value;
+
+        lex_unget_unsave(lex, c);
+
+        saved_text = strbuffer_value(&lex->saved_text);
+        value = strtol(saved_text, &end, 10);
+        assert(end == saved_text + lex->saved_text.length);
+
+        if((value == LONG_MAX && errno == ERANGE) || value > INT_MAX) {
+            error_set(error, lex, "too big integer");
+            goto out;
+        }
+        else if((value == LONG_MIN && errno == ERANGE) || value < INT_MIN) {
+            error_set(error, lex, "too big negative integer");
+            goto out;
+        }
+
+        lex->token = TOKEN_INTEGER;
+        lex->value.integer = (int)value;
+        return 0;
+    }
+
+    if(c == '.') {
+        c = lex_get(lex, error);
+        if(!isdigit(c))
+            goto out;
+        lex_save(lex, c);
+
+        c = lex_get_save(lex, error);
+        while(isdigit(c))
+            c = lex_get_save(lex, error);
+    }
+
+    if(c == 'E' || c == 'e') {
+        c = lex_get_save(lex, error);
+        if(c == '+' || c == '-')
+            c = lex_get_save(lex, error);
+
+        if(!isdigit(c)) {
+            lex_unget_unsave(lex, c);
+            goto out;
+        }
+
+        c = lex_get_save(lex, error);
+        while(isdigit(c))
+            c = lex_get_save(lex, error);
+    }
+
+    lex_unget_unsave(lex, c);
+
+    saved_text = strbuffer_value(&lex->saved_text);
+    value = strtod(saved_text, &end);
+    assert(end == saved_text + lex->saved_text.length);
+
+    if(errno == ERANGE && value != 0) {
+        error_set(error, lex, "real number overflow");
+        goto out;
+    }
+
+    lex->token = TOKEN_REAL;
+    lex->value.real = value;
+    return 0;
+
+out:
+    return -1;
+}
+
+static int lex_scan(lex_t *lex, json_error_t *error)
+{
+    char c;
+
+    strbuffer_clear(&lex->saved_text);
+
+    if(lex->token == TOKEN_STRING) {
+        free(lex->value.string);
+        lex->value.string = NULL;
+    }
+
+    c = lex_get(lex, error);
+    while(c == ' ' || c == '\t' || c == '\n' || c == '\r')
+    {
+        if(c == '\n')
+            lex->line++;
+
+        c = lex_get(lex, error);
+    }
+
+    if(c == (char)EOF) {
+        if(lex_eof(lex))
+            lex->token = TOKEN_EOF;
+        else
+            lex->token = TOKEN_INVALID;
+        goto out;
+    }
+
+    lex_save(lex, c);
+
+    if(c == '{' || c == '}' || c == '[' || c == ']' || c == ':' || c == ',')
+        lex->token = c;
+
+    else if(c == '"')
+        lex_scan_string(lex, error);
+
+    else if(isdigit(c) || c == '-') {
+        if(lex_scan_number(lex, c, error))
+            goto out;
+    }
+
+    else if(isupper(c) || islower(c)) {
+        /* eat up the whole identifier for clearer error messages */
+        const char *saved_text;
+
+        c = lex_get_save(lex, error);
+        while(isupper(c) || islower(c))
+            c = lex_get_save(lex, error);
+        lex_unget_unsave(lex, c);
+
+        saved_text = strbuffer_value(&lex->saved_text);
+
+        if(strcmp(saved_text, "true") == 0)
+            lex->token = TOKEN_TRUE;
+        else if(strcmp(saved_text, "false") == 0)
+            lex->token = TOKEN_FALSE;
+        else if(strcmp(saved_text, "null") == 0)
+            lex->token = TOKEN_NULL;
+        else
+            lex->token = TOKEN_INVALID;
+    }
+
+    else {
+        /* save the rest of the input UTF-8 sequence to get an error
+           message of valid UTF-8 */
+        lex_save_cached(lex);
+        lex->token = TOKEN_INVALID;
+    }
+
+out:
+    return lex->token;
+}
+
+static char *lex_steal_string(lex_t *lex)
+{
+    char *result = NULL;
+    if(lex->token == TOKEN_STRING)
+    {
+        result = lex->value.string;
+        lex->value.string = NULL;
+    }
+    return result;
+}
+
+static int lex_init(lex_t *lex, get_func get, eof_func eof, void *data)
+{
+    stream_init(&lex->stream, get, eof, data);
+    if(strbuffer_init(&lex->saved_text))
+        return -1;
+
+    lex->token = TOKEN_INVALID;
+    lex->line = 1;
+
+    return 0;
+}
+
+static void lex_close(lex_t *lex)
+{
+    if(lex->token == TOKEN_STRING)
+        free(lex->value.string);
+    strbuffer_close(&lex->saved_text);
+}
+
+
+/*** parser ***/
+
+static json_t *parse_value(lex_t *lex, json_error_t *error);
+
+static json_t *parse_object(lex_t *lex, json_error_t *error)
+{
+    json_t *object = json_object();
+    if(!object)
+        return NULL;
+
+    lex_scan(lex, error);
+    if(lex->token == '}')
+        return object;
+
+    while(1) {
+        char *key;
+        json_t *value;
+
+        if(lex->token != TOKEN_STRING) {
+            error_set(error, lex, "string or '}' expected");
+            goto error;
+        }
+
+        key = lex_steal_string(lex);
+        if(!key)
+            return NULL;
+
+        lex_scan(lex, error);
+        if(lex->token != ':') {
+            free(key);
+            error_set(error, lex, "':' expected");
+            goto error;
+        }
+
+        lex_scan(lex, error);
+        value = parse_value(lex, error);
+        if(!value) {
+            free(key);
+            goto error;
+        }
+
+        if(json_object_set_nocheck(object, key, value)) {
+            free(key);
+            json_decref(value);
+            goto error;
+        }
+
+        json_decref(value);
+        free(key);
+
+        lex_scan(lex, error);
+        if(lex->token != ',')
+            break;
+
+        lex_scan(lex, error);
+    }
+
+    if(lex->token != '}') {
+        error_set(error, lex, "'}' expected");
+        goto error;
+    }
+
+    return object;
+
+error:
+    json_decref(object);
+    return NULL;
+}
+
+static json_t *parse_array(lex_t *lex, json_error_t *error)
+{
+    json_t *array = json_array();
+    if(!array)
+        return NULL;
+
+    lex_scan(lex, error);
+    if(lex->token == ']')
+        return array;
+
+    while(lex->token) {
+        json_t *elem = parse_value(lex, error);
+        if(!elem)
+            goto error;
+
+        if(json_array_append(array, elem)) {
+            json_decref(elem);
+            goto error;
+        }
+        json_decref(elem);
+
+        lex_scan(lex, error);
+        if(lex->token != ',')
+            break;
+
+        lex_scan(lex, error);
+    }
+
+    if(lex->token != ']') {
+        error_set(error, lex, "']' expected");
+        goto error;
+    }
+
+    return array;
+
+error:
+    json_decref(array);
+    return NULL;
+}
+
+static json_t *parse_value(lex_t *lex, json_error_t *error)
+{
+    json_t *json;
+
+    switch(lex->token) {
+        case TOKEN_STRING: {
+            json = json_string_nocheck(lex->value.string);
+            break;
+        }
+
+        case TOKEN_INTEGER: {
+            json = json_integer(lex->value.integer);
+            break;
+        }
+
+        case TOKEN_REAL: {
+            json = json_real(lex->value.real);
+            break;
+        }
+
+        case TOKEN_TRUE:
+            json = json_true();
+            break;
+
+        case TOKEN_FALSE:
+            json = json_false();
+            break;
+
+        case TOKEN_NULL:
+            json = json_null();
+            break;
+
+        case '{':
+            json = parse_object(lex, error);
+            break;
+
+        case '[':
+            json = parse_array(lex, error);
+            break;
+
+        case TOKEN_INVALID:
+            error_set(error, lex, "invalid token");
+            return NULL;
+
+        default:
+            error_set(error, lex, "unexpected token");
+            return NULL;
+    }
+
+    if(!json)
+        return NULL;
+
+    return json;
+}
+
+static json_t *parse_json(lex_t *lex, json_error_t *error)
+{
+    error_init(error);
+
+    lex_scan(lex, error);
+    if(lex->token != '[' && lex->token != '{') {
+        error_set(error, lex, "'[' or '{' expected");
+        return NULL;
+    }
+
+    return parse_value(lex, error);
+}
+
+typedef struct
+{
+    const char *data;
+    int pos;
+} string_data_t;
+
+static int string_get(void *data)
+{
+    char c;
+    string_data_t *stream = (string_data_t *)data;
+    c = stream->data[stream->pos];
+    if(c == '\0')
+        return EOF;
+    else
+    {
+        stream->pos++;
+        return c;
+    }
+}
+
+static int string_eof(void *data)
+{
+    string_data_t *stream = (string_data_t *)data;
+    return (stream->data[stream->pos] == '\0');
+}
+
+json_t *json_loads(const char *string, json_error_t *error)
+{
+    lex_t lex;
+    json_t *result;
+
+    string_data_t stream_data = {
+        .data = string,
+        .pos = 0
+    };
+
+    if(lex_init(&lex, string_get, string_eof, (void *)&stream_data))
+        return NULL;
+
+    result = parse_json(&lex, error);
+    if(!result)
+        goto out;
+
+    lex_scan(&lex, error);
+    if(lex.token != TOKEN_EOF) {
+        error_set(error, &lex, "end of file expected");
+        json_decref(result);
+        result = NULL;
+    }
+
+out:
+    lex_close(&lex);
+    return result;
+}
+
+json_t *json_loadf(FILE *input, json_error_t *error)
+{
+    lex_t lex;
+    json_t *result;
+
+    if(lex_init(&lex, (get_func)fgetc, (eof_func)feof, input))
+        return NULL;
+
+    result = parse_json(&lex, error);
+    if(!result)
+        goto out;
+
+    lex_scan(&lex, error);
+    if(lex.token != TOKEN_EOF) {
+        error_set(error, &lex, "end of file expected");
+        json_decref(result);
+        result = NULL;
+    }
+
+out:
+    lex_close(&lex);
+    return result;
+}
+
+json_t *json_load_file(const char *path, json_error_t *error)
+{
+    json_t *result;
+    FILE *fp;
+
+    error_init(error);
+
+    fp = fopen(path, "r");
+    if(!fp)
+    {
+        error_set(error, NULL, "unable to open %s: %s",
+                  path, strerror(errno));
+        return NULL;
+    }
+
+    result = json_loadf(fp, error);
+
+    fclose(fp);
+    return result;
+}
diff --git a/compat/jansson/strbuffer.c b/compat/jansson/strbuffer.c
new file mode 100644
index 0000000..3496024
--- /dev/null
+++ b/compat/jansson/strbuffer.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <string.h>
+#include "strbuffer.h"
+#include "util.h"
+
+#define STRBUFFER_MIN_SIZE  16
+#define STRBUFFER_FACTOR    2
+
+int strbuffer_init(strbuffer_t *strbuff)
+{
+    strbuff->size = STRBUFFER_MIN_SIZE;
+    strbuff->length = 0;
+
+    strbuff->value = malloc(strbuff->size);
+    if(!strbuff->value)
+        return -1;
+
+    /* initialize to empty */
+    strbuff->value[0] = '\0';
+    return 0;
+}
+
+void strbuffer_close(strbuffer_t *strbuff)
+{
+    free(strbuff->value);
+    strbuff->size = 0;
+    strbuff->length = 0;
+    strbuff->value = NULL;
+}
+
+void strbuffer_clear(strbuffer_t *strbuff)
+{
+    strbuff->length = 0;
+    strbuff->value[0] = '\0';
+}
+
+const char *strbuffer_value(const strbuffer_t *strbuff)
+{
+    return strbuff->value;
+}
+
+char *strbuffer_steal_value(strbuffer_t *strbuff)
+{
+    char *result = strbuff->value;
+    strbuffer_init(strbuff);
+    return result;
+}
+
+int strbuffer_append(strbuffer_t *strbuff, const char *string)
+{
+    return strbuffer_append_bytes(strbuff, string, strlen(string));
+}
+
+int strbuffer_append_byte(strbuffer_t *strbuff, char byte)
+{
+    return strbuffer_append_bytes(strbuff, &byte, 1);
+}
+
+int strbuffer_append_bytes(strbuffer_t *strbuff, const char *data, int size)
+{
+    if(strbuff->length + size >= strbuff->size)
+    {
+        strbuff->size = max(strbuff->size * STRBUFFER_FACTOR,
+                            strbuff->length + size + 1);
+
+        strbuff->value = realloc(strbuff->value, strbuff->size);
+        if(!strbuff->value)
+            return -1;
+    }
+
+    memcpy(strbuff->value + strbuff->length, data, size);
+    strbuff->length += size;
+    strbuff->value[strbuff->length] = '\0';
+
+    return 0;
+}
+
+char strbuffer_pop(strbuffer_t *strbuff)
+{
+    if(strbuff->length > 0) {
+        char c = strbuff->value[--strbuff->length];
+        strbuff->value[strbuff->length] = '\0';
+        return c;
+    }
+    else
+        return '\0';
+}
diff --git a/compat/jansson/strbuffer.h b/compat/jansson/strbuffer.h
new file mode 100644
index 0000000..f4c5f77
--- /dev/null
+++ b/compat/jansson/strbuffer.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef STRBUFFER_H
+#define STRBUFFER_H
+
+typedef struct {
+    char *value;
+    int length;   /* bytes used */
+    int size;     /* bytes allocated */
+} strbuffer_t;
+
+int strbuffer_init(strbuffer_t *strbuff);
+void strbuffer_close(strbuffer_t *strbuff);
+
+void strbuffer_clear(strbuffer_t *strbuff);
+
+const char *strbuffer_value(const strbuffer_t *strbuff);
+char *strbuffer_steal_value(strbuffer_t *strbuff);
+
+int strbuffer_append(strbuffer_t *strbuff, const char *string);
+int strbuffer_append_byte(strbuffer_t *strbuff, char byte);
+int strbuffer_append_bytes(strbuffer_t *strbuff, const char *data, int size);
+
+char strbuffer_pop(strbuffer_t *strbuff);
+
+#endif
diff --git a/compat/jansson/utf.c b/compat/jansson/utf.c
new file mode 100644
index 0000000..92484d0
--- /dev/null
+++ b/compat/jansson/utf.c
@@ -0,0 +1,190 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <string.h>
+#include "utf.h"
+
+int utf8_encode(int32_t codepoint, char *buffer, int *size)
+{
+    if(codepoint < 0)
+        return -1;
+    else if(codepoint < 0x80)
+    {
+        buffer[0] = (char)codepoint;
+        *size = 1;
+    }
+    else if(codepoint < 0x800)
+    {
+        buffer[0] = 0xC0 + ((codepoint & 0x7C0) >> 6);
+        buffer[1] = 0x80 + ((codepoint & 0x03F));
+        *size = 2;
+    }
+    else if(codepoint < 0x10000)
+    {
+        buffer[0] = 0xE0 + ((codepoint & 0xF000) >> 12);
+        buffer[1] = 0x80 + ((codepoint & 0x0FC0) >> 6);
+        buffer[2] = 0x80 + ((codepoint & 0x003F));
+        *size = 3;
+    }
+    else if(codepoint <= 0x10FFFF)
+    {
+        buffer[0] = 0xF0 + ((codepoint & 0x1C0000) >> 18);
+        buffer[1] = 0x80 + ((codepoint & 0x03F000) >> 12);
+        buffer[2] = 0x80 + ((codepoint & 0x000FC0) >> 6);
+        buffer[3] = 0x80 + ((codepoint & 0x00003F));
+        *size = 4;
+    }
+    else
+        return -1;
+
+    return 0;
+}
+
+int utf8_check_first(char byte)
+{
+    unsigned char u = (unsigned char)byte;
+
+    if(u < 0x80)
+        return 1;
+
+    if(0x80 <= u && u <= 0xBF) {
+        /* second, third or fourth byte of a multi-byte
+           sequence, i.e. a "continuation byte" */
+        return 0;
+    }
+    else if(u == 0xC0 || u == 0xC1) {
+        /* overlong encoding of an ASCII byte */
+        return 0;
+    }
+    else if(0xC2 <= u && u <= 0xDF) {
+        /* 2-byte sequence */
+        return 2;
+    }
+
+    else if(0xE0 <= u && u <= 0xEF) {
+        /* 3-byte sequence */
+        return 3;
+    }
+    else if(0xF0 <= u && u <= 0xF4) {
+        /* 4-byte sequence */
+        return 4;
+    }
+    else { /* u >= 0xF5 */
+        /* Restricted (start of 4-, 5- or 6-byte sequence) or invalid
+           UTF-8 */
+        return 0;
+    }
+}
+
+int utf8_check_full(const char *buffer, int size, int32_t *codepoint)
+{
+    int i;
+    int32_t value = 0;
+    unsigned char u = (unsigned char)buffer[0];
+
+    if(size == 2)
+    {
+        value = u & 0x1F;
+    }
+    else if(size == 3)
+    {
+        value = u & 0xF;
+    }
+    else if(size == 4)
+    {
+        value = u & 0x7;
+    }
+    else
+        return 0;
+
+    for(i = 1; i < size; i++)
+    {
+        u = (unsigned char)buffer[i];
+
+        if(u < 0x80 || u > 0xBF) {
+            /* not a continuation byte */
+            return 0;
+        }
+
+        value = (value << 6) + (u & 0x3F);
+    }
+
+    if(value > 0x10FFFF) {
+        /* not in Unicode range */
+        return 0;
+    }
+
+    else if(0xD800 <= value && value <= 0xDFFF) {
+        /* invalid code point (UTF-16 surrogate halves) */
+        return 0;
+    }
+
+    else if((size == 2 && value < 0x80) ||
+            (size == 3 && value < 0x800) ||
+            (size == 4 && value < 0x10000)) {
+        /* overlong encoding */
+        return 0;
+    }
+
+    if(codepoint)
+        *codepoint = value;
+
+    return 1;
+}
+
+const char *utf8_iterate(const char *buffer, int32_t *codepoint)
+{
+    int count;
+    int32_t value;
+
+    if(!*buffer)
+        return buffer;
+
+    count = utf8_check_first(buffer[0]);
+    if(count <= 0)
+        return NULL;
+
+    if(count == 1)
+        value = (unsigned char)buffer[0];
+    else
+    {
+        if(!utf8_check_full(buffer, count, &value))
+            return NULL;
+    }
+
+    if(codepoint)
+        *codepoint = value;
+
+    return buffer + count;
+}
+
+int utf8_check_string(const char *string, int length)
+{
+    int i;
+
+    if(length == -1)
+        length = strlen(string);
+
+    for(i = 0; i < length; i++)
+    {
+        int count = utf8_check_first(string[i]);
+        if(count == 0)
+            return 0;
+        else if(count > 1)
+        {
+            if(i + count > length)
+                return 0;
+
+            if(!utf8_check_full(&string[i], count, NULL))
+                return 0;
+
+            i += count - 1;
+        }
+    }
+
+    return 1;
+}
diff --git a/compat/jansson/utf.h b/compat/jansson/utf.h
new file mode 100644
index 0000000..d0ae6e9
--- /dev/null
+++ b/compat/jansson/utf.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef UTF_H
+#define UTF_H
+
+#include <config.h>
+
+#ifdef HAVE_INTTYPES_H
+/* inttypes.h includes stdint.h in a standard environment, so there's
+no need to include stdint.h separately. If inttypes.h doesn't define
+int32_t, it's defined in config.h. */
+#include <inttypes.h>
+#endif
+
+int utf8_encode(int codepoint, char *buffer, int *size);
+
+int utf8_check_first(char byte);
+int utf8_check_full(const char *buffer, int size, int32_t *codepoint);
+const char *utf8_iterate(const char *buffer, int32_t *codepoint);
+
+int utf8_check_string(const char *string, int length);
+
+#endif
diff --git a/compat/jansson/util.h b/compat/jansson/util.h
new file mode 100644
index 0000000..06a547b
--- /dev/null
+++ b/compat/jansson/util.h
@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef UTIL_H
+#define UTIL_H
+
+#define max(a, b)  ((a) > (b) ? (a) : (b))
+
+#endif
diff --git a/compat/jansson/value.c b/compat/jansson/value.c
new file mode 100644
index 0000000..e024fdb
--- /dev/null
+++ b/compat/jansson/value.c
@@ -0,0 +1,976 @@
+/*
+ * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#define _GNU_SOURCE
+
+#include <config.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <jansson.h>
+#include "hashtable.h"
+#include "jansson_private.h"
+#include "utf.h"
+#include "util.h"
+
+
+static inline void json_init(json_t *json, json_type type)
+{
+    json->type = type;
+    json->refcount = 1;
+}
+
+
+/*** object ***/
+
+/* This macro just returns a pointer that's a few bytes backwards from
+   string. This makes it possible to pass a pointer to object_key_t
+   when only the string inside it is used, without actually creating
+   an object_key_t instance. */
+#define string_to_key(string)  container_of(string, object_key_t, key)
+
+static unsigned int hash_key(const void *ptr)
+{
+    const char *str = ((const object_key_t *)ptr)->key;
+
+    unsigned int hash = 5381;
+    unsigned int c;
+
+    while((c = (unsigned int)*str))
+    {
+        hash = ((hash << 5) + hash) + c;
+        str++;
+    }
+
+    return hash;
+}
+
+static int key_equal(const void *ptr1, const void *ptr2)
+{
+    return strcmp(((const object_key_t *)ptr1)->key,
+                  ((const object_key_t *)ptr2)->key) == 0;
+}
+
+static void value_decref(void *value)
+{
+    json_decref((json_t *)value);
+}
+
+json_t *json_object(void)
+{
+    json_object_t *object = malloc(sizeof(json_object_t));
+    if(!object)
+        return NULL;
+    json_init(&object->json, JSON_OBJECT);
+
+    if(hashtable_init(&object->hashtable, hash_key, key_equal,
+                      free, value_decref))
+    {
+        free(object);
+        return NULL;
+    }
+
+    object->serial = 0;
+    object->visited = 0;
+
+    return &object->json;
+}
+
+static void json_delete_object(json_object_t *object)
+{
+    hashtable_close(&object->hashtable);
+    free(object);
+}
+
+unsigned int json_object_size(const json_t *json)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return -1;
+
+    object = json_to_object(json);
+    return object->hashtable.size;
+}
+
+json_t *json_object_get(const json_t *json, const char *key)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_get(&object->hashtable, string_to_key(key));
+}
+
+int json_object_set_new_nocheck(json_t *json, const char *key, json_t *value)
+{
+    json_object_t *object;
+    object_key_t *k;
+
+    if(!key || !value)
+        return -1;
+
+    if(!json_is_object(json) || json == value)
+    {
+        json_decref(value);
+        return -1;
+    }
+    object = json_to_object(json);
+
+    k = malloc(sizeof(object_key_t) + strlen(key) + 1);
+    if(!k)
+        return -1;
+
+    k->serial = object->serial++;
+    strcpy(k->key, key);
+
+    if(hashtable_set(&object->hashtable, k, value))
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    return 0;
+}
+
+int json_object_set_new(json_t *json, const char *key, json_t *value)
+{
+    if(!key || !utf8_check_string(key, -1))
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    return json_object_set_new_nocheck(json, key, value);
+}
+
+int json_object_del(json_t *json, const char *key)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return -1;
+
+    object = json_to_object(json);
+    return hashtable_del(&object->hashtable, string_to_key(key));
+}
+
+int json_object_clear(json_t *json)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return -1;
+
+    object = json_to_object(json);
+    hashtable_clear(&object->hashtable);
+
+    return 0;
+}
+
+int json_object_update(json_t *object, json_t *other)
+{
+    void *iter;
+
+    if(!json_is_object(object) || !json_is_object(other))
+        return -1;
+
+    iter = json_object_iter(other);
+    while(iter) {
+        const char *key;
+        json_t *value;
+
+        key = json_object_iter_key(iter);
+        value = json_object_iter_value(iter);
+
+        if(json_object_set_nocheck(object, key, value))
+            return -1;
+
+        iter = json_object_iter_next(other, iter);
+    }
+
+    return 0;
+}
+
+void *json_object_iter(json_t *json)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_iter(&object->hashtable);
+}
+
+void *json_object_iter_at(json_t *json, const char *key)
+{
+    json_object_t *object;
+
+    if(!key || !json_is_object(json))
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_iter_at(&object->hashtable, string_to_key(key));
+}
+
+void *json_object_iter_next(json_t *json, void *iter)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json) || iter == NULL)
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_iter_next(&object->hashtable, iter);
+}
+
+const object_key_t *jsonp_object_iter_fullkey(void *iter)
+{
+    if(!iter)
+        return NULL;
+
+    return hashtable_iter_key(iter);
+}
+
+const char *json_object_iter_key(void *iter)
+{
+    if(!iter)
+        return NULL;
+
+    return jsonp_object_iter_fullkey(iter)->key;
+}
+
+json_t *json_object_iter_value(void *iter)
+{
+    if(!iter)
+        return NULL;
+
+    return (json_t *)hashtable_iter_value(iter);
+}
+
+int json_object_iter_set_new(json_t *json, void *iter, json_t *value)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json) || !iter || !value)
+        return -1;
+
+    object = json_to_object(json);
+    hashtable_iter_set(&object->hashtable, iter, value);
+
+    return 0;
+}
+
+static int json_object_equal(json_t *object1, json_t *object2)
+{
+    void *iter;
+
+    if(json_object_size(object1) != json_object_size(object2))
+        return 0;
+
+    iter = json_object_iter(object1);
+    while(iter)
+    {
+        const char *key;
+        json_t *value1, *value2;
+
+        key = json_object_iter_key(iter);
+        value1 = json_object_iter_value(iter);
+        value2 = json_object_get(object2, key);
+
+        if(!json_equal(value1, value2))
+            return 0;
+
+        iter = json_object_iter_next(object1, iter);
+    }
+
+    return 1;
+}
+
+static json_t *json_object_copy(json_t *object)
+{
+    json_t *result;
+    void *iter;
+
+    result = json_object();
+    if(!result)
+        return NULL;
+
+    iter = json_object_iter(object);
+    while(iter)
+    {
+        const char *key;
+        json_t *value;
+
+        key = json_object_iter_key(iter);
+        value = json_object_iter_value(iter);
+        json_object_set_nocheck(result, key, value);
+
+        iter = json_object_iter_next(object, iter);
+    }
+
+    return result;
+}
+
+static json_t *json_object_deep_copy(json_t *object)
+{
+    json_t *result;
+    void *iter;
+
+    result = json_object();
+    if(!result)
+        return NULL;
+
+    iter = json_object_iter(object);
+    while(iter)
+    {
+        const char *key;
+        json_t *value;
+
+        key = json_object_iter_key(iter);
+        value = json_object_iter_value(iter);
+        json_object_set_new_nocheck(result, key, json_deep_copy(value));
+
+        iter = json_object_iter_next(object, iter);
+    }
+
+    return result;
+}
+
+
+/*** array ***/
+
+json_t *json_array(void)
+{
+    json_array_t *array = malloc(sizeof(json_array_t));
+    if(!array)
+        return NULL;
+    json_init(&array->json, JSON_ARRAY);
+
+    array->entries = 0;
+    array->size = 8;
+
+    array->table = malloc(array->size * sizeof(json_t *));
+    if(!array->table) {
+        free(array);
+        return NULL;
+    }
+
+    array->visited = 0;
+
+    return &array->json;
+}
+
+static void json_delete_array(json_array_t *array)
+{
+    unsigned int i;
+
+    for(i = 0; i < array->entries; i++)
+        json_decref(array->table[i]);
+
+    free(array->table);
+    free(array);
+}
+
+unsigned int json_array_size(const json_t *json)
+{
+    if(!json_is_array(json))
+        return 0;
+
+    return json_to_array(json)->entries;
+}
+
+json_t *json_array_get(const json_t *json, unsigned int index)
+{
+    json_array_t *array;
+    if(!json_is_array(json))
+        return NULL;
+    array = json_to_array(json);
+
+    if(index >= array->entries)
+        return NULL;
+
+    return array->table[index];
+}
+
+int json_array_set_new(json_t *json, unsigned int index, json_t *value)
+{
+    json_array_t *array;
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value)
+    {
+        json_decref(value);
+        return -1;
+    }
+    array = json_to_array(json);
+
+    if(index >= array->entries)
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    json_decref(array->table[index]);
+    array->table[index] = value;
+
+    return 0;
+}
+
+static void array_move(json_array_t *array, unsigned int dest,
+                       unsigned int src, unsigned int count)
+{
+    memmove(&array->table[dest], &array->table[src], count * sizeof(json_t *));
+}
+
+static void array_copy(json_t **dest, unsigned int dpos,
+                       json_t **src, unsigned int spos,
+                       unsigned int count)
+{
+    memcpy(&dest[dpos], &src[spos], count * sizeof(json_t *));
+}
+
+static json_t **json_array_grow(json_array_t *array,
+                                unsigned int amount,
+                                int copy)
+{
+    unsigned int new_size;
+    json_t **old_table, **new_table;
+
+    if(array->entries + amount <= array->size)
+        return array->table;
+
+    old_table = array->table;
+
+    new_size = max(array->size + amount, array->size * 2);
+    new_table = malloc(new_size * sizeof(json_t *));
+    if(!new_table)
+        return NULL;
+
+    array->size = new_size;
+    array->table = new_table;
+
+    if(copy) {
+        array_copy(array->table, 0, old_table, 0, array->entries);
+        free(old_table);
+        return array->table;
+    }
+
+    return old_table;
+}
+
+int json_array_append_new(json_t *json, json_t *value)
+{
+    json_array_t *array;
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value)
+    {
+        json_decref(value);
+        return -1;
+    }
+    array = json_to_array(json);
+
+    if(!json_array_grow(array, 1, 1)) {
+        json_decref(value);
+        return -1;
+    }
+
+    array->table[array->entries] = value;
+    array->entries++;
+
+    return 0;
+}
+
+int json_array_insert_new(json_t *json, unsigned int index, json_t *value)
+{
+    json_array_t *array;
+    json_t **old_table;
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value) {
+        json_decref(value);
+        return -1;
+    }
+    array = json_to_array(json);
+
+    if(index > array->entries) {
+        json_decref(value);
+        return -1;
+    }
+
+    old_table = json_array_grow(array, 1, 0);
+    if(!old_table) {
+        json_decref(value);
+        return -1;
+    }
+
+    if(old_table != array->table) {
+        array_copy(array->table, 0, old_table, 0, index);
+        array_copy(array->table, index + 1, old_table, index,
+                   array->entries - index);
+        free(old_table);
+    }
+    else
+        array_move(array, index + 1, index, array->entries - index);
+
+    array->table[index] = value;
+    array->entries++;
+
+    return 0;
+}
+
+int json_array_remove(json_t *json, unsigned int index)
+{
+    json_array_t *array;
+
+    if(!json_is_array(json))
+        return -1;
+    array = json_to_array(json);
+
+    if(index >= array->entries)
+        return -1;
+
+    json_decref(array->table[index]);
+
+    array_move(array, index, index + 1, array->entries - index);
+    array->entries--;
+
+    return 0;
+}
+
+int json_array_clear(json_t *json)
+{
+    json_array_t *array;
+    unsigned int i;
+
+    if(!json_is_array(json))
+        return -1;
+    array = json_to_array(json);
+
+    for(i = 0; i < array->entries; i++)
+        json_decref(array->table[i]);
+
+    array->entries = 0;
+    return 0;
+}
+
+int json_array_extend(json_t *json, json_t *other_json)
+{
+    json_array_t *array, *other;
+    unsigned int i;
+
+    if(!json_is_array(json) || !json_is_array(other_json))
+        return -1;
+    array = json_to_array(json);
+    other = json_to_array(other_json);
+
+    if(!json_array_grow(array, other->entries, 1))
+        return -1;
+
+    for(i = 0; i < other->entries; i++)
+        json_incref(other->table[i]);
+
+    array_copy(array->table, array->entries, other->table, 0, other->entries);
+
+    array->entries += other->entries;
+    return 0;
+}
+
+static int json_array_equal(json_t *array1, json_t *array2)
+{
+    unsigned int i, size;
+
+    size = json_array_size(array1);
+    if(size != json_array_size(array2))
+        return 0;
+
+    for(i = 0; i < size; i++)
+    {
+        json_t *value1, *value2;
+
+        value1 = json_array_get(array1, i);
+        value2 = json_array_get(array2, i);
+
+        if(!json_equal(value1, value2))
+            return 0;
+    }
+
+    return 1;
+}
+
+static json_t *json_array_copy(json_t *array)
+{
+    json_t *result;
+    unsigned int i;
+
+    result = json_array();
+    if(!result)
+        return NULL;
+
+    for(i = 0; i < json_array_size(array); i++)
+        json_array_append(result, json_array_get(array, i));
+
+    return result;
+}
+
+static json_t *json_array_deep_copy(json_t *array)
+{
+    json_t *result;
+    unsigned int i;
+
+    result = json_array();
+    if(!result)
+        return NULL;
+
+    for(i = 0; i < json_array_size(array); i++)
+        json_array_append_new(result, json_deep_copy(json_array_get(array, i)));
+
+    return result;
+}
+
+/*** string ***/
+
+json_t *json_string_nocheck(const char *value)
+{
+    json_string_t *string;
+
+    if(!value)
+        return NULL;
+
+    string = malloc(sizeof(json_string_t));
+    if(!string)
+        return NULL;
+    json_init(&string->json, JSON_STRING);
+
+    string->value = strdup(value);
+    if(!string->value) {
+        free(string);
+        return NULL;
+    }
+
+    return &string->json;
+}
+
+json_t *json_string(const char *value)
+{
+    if(!value || !utf8_check_string(value, -1))
+        return NULL;
+
+    return json_string_nocheck(value);
+}
+
+const char *json_string_value(const json_t *json)
+{
+    if(!json_is_string(json))
+        return NULL;
+
+    return json_to_string(json)->value;
+}
+
+int json_string_set_nocheck(json_t *json, const char *value)
+{
+    char *dup;
+    json_string_t *string;
+
+    dup = strdup(value);
+    if(!dup)
+        return -1;
+
+    string = json_to_string(json);
+    free(string->value);
+    string->value = dup;
+
+    return 0;
+}
+
+int json_string_set(json_t *json, const char *value)
+{
+    if(!value || !utf8_check_string(value, -1))
+        return -1;
+
+    return json_string_set_nocheck(json, value);
+}
+
+static void json_delete_string(json_string_t *string)
+{
+    free(string->value);
+    free(string);
+}
+
+static int json_string_equal(json_t *string1, json_t *string2)
+{
+    return strcmp(json_string_value(string1), json_string_value(string2)) == 0;
+}
+
+static json_t *json_string_copy(json_t *string)
+{
+    return json_string_nocheck(json_string_value(string));
+}
+
+
+/*** integer ***/
+
+json_t *json_integer(int value)
+{
+    json_integer_t *integer = malloc(sizeof(json_integer_t));
+    if(!integer)
+        return NULL;
+    json_init(&integer->json, JSON_INTEGER);
+
+    integer->value = value;
+    return &integer->json;
+}
+
+int json_integer_value(const json_t *json)
+{
+    if(!json_is_integer(json))
+        return 0;
+
+    return json_to_integer(json)->value;
+}
+
+int json_integer_set(json_t *json, int value)
+{
+    if(!json_is_integer(json))
+        return -1;
+
+    json_to_integer(json)->value = value;
+
+    return 0;
+}
+
+static void json_delete_integer(json_integer_t *integer)
+{
+    free(integer);
+}
+
+static int json_integer_equal(json_t *integer1, json_t *integer2)
+{
+    return json_integer_value(integer1) == json_integer_value(integer2);
+}
+
+static json_t *json_integer_copy(json_t *integer)
+{
+    return json_integer(json_integer_value(integer));
+}
+
+
+/*** real ***/
+
+json_t *json_real(double value)
+{
+    json_real_t *real = malloc(sizeof(json_real_t));
+    if(!real)
+        return NULL;
+    json_init(&real->json, JSON_REAL);
+
+    real->value = value;
+    return &real->json;
+}
+
+double json_real_value(const json_t *json)
+{
+    if(!json_is_real(json))
+        return 0;
+
+    return json_to_real(json)->value;
+}
+
+int json_real_set(json_t *json, double value)
+{
+    if(!json_is_real(json))
+        return 0;
+
+    json_to_real(json)->value = value;
+
+    return 0;
+}
+
+static void json_delete_real(json_real_t *real)
+{
+    free(real);
+}
+
+static int json_real_equal(json_t *real1, json_t *real2)
+{
+    return json_real_value(real1) == json_real_value(real2);
+}
+
+static json_t *json_real_copy(json_t *real)
+{
+    return json_real(json_real_value(real));
+}
+
+
+/*** number ***/
+
+double json_number_value(const json_t *json)
+{
+    if(json_is_integer(json))
+        return json_integer_value(json);
+    else if(json_is_real(json))
+        return json_real_value(json);
+    else
+        return 0.0;
+}
+
+
+/*** simple values ***/
+
+json_t *json_true(void)
+{
+    static json_t the_true = {
+        .type = JSON_TRUE,
+        .refcount = (unsigned int)-1
+    };
+    return &the_true;
+}
+
+
+json_t *json_false(void)
+{
+    static json_t the_false = {
+        .type = JSON_FALSE,
+        .refcount = (unsigned int)-1
+    };
+    return &the_false;
+}
+
+
+json_t *json_null(void)
+{
+    static json_t the_null = {
+        .type = JSON_NULL,
+        .refcount = (unsigned int)-1
+    };
+    return &the_null;
+}
+
+
+/*** deletion ***/
+
+void json_delete(json_t *json)
+{
+    if(json_is_object(json))
+        json_delete_object(json_to_object(json));
+
+    else if(json_is_array(json))
+        json_delete_array(json_to_array(json));
+
+    else if(json_is_string(json))
+        json_delete_string(json_to_string(json));
+
+    else if(json_is_integer(json))
+        json_delete_integer(json_to_integer(json));
+
+    else if(json_is_real(json))
+        json_delete_real(json_to_real(json));
+
+    /* json_delete is not called for true, false or null */
+}
+
+
+/*** equality ***/
+
+int json_equal(json_t *json1, json_t *json2)
+{
+    if(!json1 || !json2)
+        return 0;
+
+    if(json_typeof(json1) != json_typeof(json2))
+        return 0;
+
+    /* this covers true, false and null as they are singletons */
+    if(json1 == json2)
+        return 1;
+
+    if(json_is_object(json1))
+        return json_object_equal(json1, json2);
+
+    if(json_is_array(json1))
+        return json_array_equal(json1, json2);
+
+    if(json_is_string(json1))
+        return json_string_equal(json1, json2);
+
+    if(json_is_integer(json1))
+        return json_integer_equal(json1, json2);
+
+    if(json_is_real(json1))
+        return json_real_equal(json1, json2);
+
+    return 0;
+}
+
+
+/*** copying ***/
+
+json_t *json_copy(json_t *json)
+{
+    if(!json)
+        return NULL;
+
+    if(json_is_object(json))
+        return json_object_copy(json);
+
+    if(json_is_array(json))
+        return json_array_copy(json);
+
+    if(json_is_string(json))
+        return json_string_copy(json);
+
+    if(json_is_integer(json))
+        return json_integer_copy(json);
+
+    if(json_is_real(json))
+        return json_real_copy(json);
+
+    if(json_is_true(json) || json_is_false(json) || json_is_null(json))
+        return json;
+
+    return NULL;
+}
+
+json_t *json_deep_copy(json_t *json)
+{
+    if(!json)
+        return NULL;
+
+    if(json_is_object(json))
+        return json_object_deep_copy(json);
+
+    if(json_is_array(json))
+        return json_array_deep_copy(json);
+
+    /* for the rest of the types, deep copying doesn't differ from
+       shallow copying */
+
+    if(json_is_string(json))
+        return json_string_copy(json);
+
+    if(json_is_integer(json))
+        return json_integer_copy(json);
+
+    if(json_is_real(json))
+        return json_real_copy(json);
+
+    if(json_is_true(json) || json_is_false(json) || json_is_null(json))
+        return json;
+
+    return NULL;
+}