Imported Upstream version 0.9.2upstream/0.9.2

1 files changed, 768 insertions, 0 deletions

diff --git a/src/include/gnunet_disk_lib.h b/src/include/gnunet_disk_lib.h
new file mode 100644
index 0000000..18f5535
--- /dev/null
+++ b/src/include/gnunet_disk_lib.h
@@ -0,0 +1,768 @@
+/*
+     This file is part of GNUnet.
+     (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 2, or (at your
+     option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file include/gnunet_disk_lib.h
+ * @brief disk IO apis
+ */
+#ifndef GNUNET_DISK_LIB_H
+#define GNUNET_DISK_LIB_H
+
+#if WINDOWS
+#define OFF_T uint64_t
+#else
+#define OFF_T off_t
+#endif
+
+/**
+ * Handle used to manage a pipe.
+ */
+struct GNUNET_DISK_PipeHandle;
+
+
+enum GNUNET_FILE_Type
+{
+  GNUNET_DISK_FILE, GNUNET_PIPE
+};
+
+/**
+ * Handle used to access files (and pipes).
+ */
+struct GNUNET_DISK_FileHandle
+{
+
+#if WINDOWS
+  /**
+   * File handle under W32.
+   */
+  HANDLE h;
+
+  /**
+   * Type
+   */
+  enum GNUNET_FILE_Type type;
+
+  /**
+   * Structure for overlapped reading (for pipes)
+   */
+  OVERLAPPED *oOverlapRead;
+
+  /**
+   * Structure for overlapped writing (for pipes)
+   */
+  OVERLAPPED *oOverlapWrite;
+#else
+
+  /**
+   * File handle on other OSes.
+   */
+  int fd;
+
+#endif                          /*
+                                 */
+};
+
+
+/* we need size_t, and since it can be both unsigned int
+   or unsigned long long, this IS platform dependent;
+   but "stdlib.h" should be portable 'enough' to be
+   unconditionally available... */
+#include <stdlib.h>
+#include "gnunet_configuration_lib.h"
+#include "gnunet_scheduler_lib.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#if 0                           /* keep Emacsens' auto-indent happy */
+}
+#endif
+#endif
+
+
+/**
+ * Specifies how a file should be opened.
+ */
+enum GNUNET_DISK_OpenFlags
+{
+
+    /**
+     * Open the file for reading
+     */
+  GNUNET_DISK_OPEN_READ = 1,
+
+    /**
+     * Open the file for writing
+     */
+  GNUNET_DISK_OPEN_WRITE = 2,
+
+    /**
+     * Open the file for both reading and writing
+     */
+  GNUNET_DISK_OPEN_READWRITE = 3,
+
+    /**
+     * Fail if file already exists
+     */
+  GNUNET_DISK_OPEN_FAILIFEXISTS = 4,
+
+    /**
+     * Truncate file if it exists
+     */
+  GNUNET_DISK_OPEN_TRUNCATE = 8,
+
+    /**
+     * Create file if it doesn't exist
+     */
+  GNUNET_DISK_OPEN_CREATE = 16,
+
+    /**
+     * Append to the file
+     */
+  GNUNET_DISK_OPEN_APPEND = 32
+};
+
+/**
+ * Specifies what type of memory map is desired.
+ */
+enum GNUNET_DISK_MapType
+{
+    /**
+     * Read-only memory map.
+     */
+  GNUNET_DISK_MAP_TYPE_READ = 1,
+
+    /**
+     * Write-able memory map.
+     */
+  GNUNET_DISK_MAP_TYPE_WRITE = 2,
+    /**
+     * Read-write memory map.
+     */
+  GNUNET_DISK_MAP_TYPE_READWRITE = 3
+};
+
+
+/**
+ * File access permissions, UNIX-style.
+ */
+enum GNUNET_DISK_AccessPermissions
+{
+    /**
+     * Nobody is allowed to do anything to the file.
+     */
+  GNUNET_DISK_PERM_NONE = 0,
+
+    /**
+     * Owner can read.
+     */
+  GNUNET_DISK_PERM_USER_READ = 1,
+
+    /**
+     * Owner can write.
+     */
+  GNUNET_DISK_PERM_USER_WRITE = 2,
+
+    /**
+     * Owner can execute.
+     */
+  GNUNET_DISK_PERM_USER_EXEC = 4,
+
+    /**
+     * Group can read.
+     */
+  GNUNET_DISK_PERM_GROUP_READ = 8,
+
+    /**
+     * Group can write.
+     */
+  GNUNET_DISK_PERM_GROUP_WRITE = 16,
+
+    /**
+     * Group can execute.
+     */
+  GNUNET_DISK_PERM_GROUP_EXEC = 32,
+
+    /**
+     * Everybody can read.
+     */
+  GNUNET_DISK_PERM_OTHER_READ = 64,
+
+    /**
+     * Everybody can write.
+     */
+  GNUNET_DISK_PERM_OTHER_WRITE = 128,
+
+    /**
+     * Everybody can execute.
+     */
+  GNUNET_DISK_PERM_OTHER_EXEC = 256
+};
+
+
+/**
+ * Constants for specifying how to seek.
+ */
+enum GNUNET_DISK_Seek
+{
+    /**
+     * Seek an absolute position (from the start of the file).
+     */
+  GNUNET_DISK_SEEK_SET,
+
+    /**
+     * Seek a relative position (from the current offset).
+     */
+  GNUNET_DISK_SEEK_CUR,
+
+    /**
+     * Seek an absolute position from the end of the file.
+     */
+  GNUNET_DISK_SEEK_END
+};
+
+
+/**
+ * Enumeration identifying the two ends of a pipe.
+ */
+enum GNUNET_DISK_PipeEnd
+{
+    /**
+     * The reading-end of a pipe.
+     */
+  GNUNET_DISK_PIPE_END_READ = 0,
+
+    /**
+     * The writing-end of a pipe.
+     */
+  GNUNET_DISK_PIPE_END_WRITE = 1
+};
+
+
+/**
+ * Get the number of blocks that are left on the partition that
+ * contains the given file (for normal users).
+ *
+ * @param part a file on the partition to check
+ * @return -1 on errors, otherwise the number of free blocks
+ */
+long
+GNUNET_DISK_get_blocks_available (const char *part);
+
+
+/**
+ * Checks whether a handle is invalid
+ *
+ * @param h handle to check
+ * @return GNUNET_YES if invalid, GNUNET_NO if valid
+ */
+int
+GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
+
+
+/**
+ * Check that fil corresponds to a filename
+ * (of a file that exists and that is not a directory).
+ *
+ * @param fil filename to check
+ * @return GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
+ * else (will print an error message in that case, too).
+ */
+int
+GNUNET_DISK_file_test (const char *fil);
+
+
+/**
+ * Move the read/write pointer in a file
+ * @param h handle of an open file
+ * @param offset position to move to
+ * @param whence specification to which position the offset parameter relates to
+ * @return the new position on success, GNUNET_SYSERR otherwise
+ */
+OFF_T
+GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h, OFF_T offset,
+                       enum GNUNET_DISK_Seek whence);
+
+
+/**
+ * Get the size of the file (or directory)
+ * of the given file (in bytes).
+ *
+ * @param filename name of the file or directory
+ * @param size set to the size of the file (or,
+ *             in the case of directories, the sum
+ *             of all sizes of files in the directory)
+ * @param includeSymLinks should symbolic links be
+ *        included?
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_file_size (const char *filename, uint64_t * size,
+                       int includeSymLinks);
+
+
+/**
+ * Obtain some unique identifiers for the given file
+ * that can be used to identify it in the local system.
+ * This function is used between GNUnet processes to
+ * quickly check if two files with the same absolute path
+ * are actually identical.  The two processes represent
+ * the same peer but may communicate over the network
+ * (and the file may be on an NFS volume).  This function
+ * may not be supported on all operating systems.
+ *
+ * @param filename name of the file
+ * @param dev set to the device ID
+ * @param ino set to the inode ID
+ * @return GNUNET_OK on success
+ */
+int
+GNUNET_DISK_file_get_identifiers (const char *filename, uint64_t * dev,
+                                  uint64_t * ino);
+
+
+/**
+ * Create an (empty) temporary file on disk.  If the given name is not
+ * an absolute path, the current 'TMPDIR' will be prepended.  In any case,
+ * 6 random characters will be appended to the name to create a unique
+ * filename.
+ *
+ * @param t component to use for the name;
+ *        does NOT contain "XXXXXX" or "/tmp/".
+ * @return NULL on error, otherwise name of fresh
+ *         file on disk in directory for temporary files
+ */
+char *
+GNUNET_DISK_mktemp (const char *t);
+
+
+/**
+ * Open a file.  Note that the access permissions will only be
+ * used if a new file is created and if the underlying operating
+ * system supports the given permissions.
+ *
+ * @param fn file name to be opened
+ * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
+ * @param perm permissions for the newly created file, use
+ *             GNUNET_DISK_PERM_NONE if a file could not be created by this
+ *             call (because of flags)
+ * @return IO handle on success, NULL on error
+ */
+struct GNUNET_DISK_FileHandle *
+GNUNET_DISK_file_open (const char *fn, enum GNUNET_DISK_OpenFlags flags,
+                       enum GNUNET_DISK_AccessPermissions perm);
+
+
+/**
+ * Get the size of an open file.
+ *
+ * @param fh open file handle
+ * @param size where to write size of the file
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_file_handle_size (struct GNUNET_DISK_FileHandle *fh,
+			      OFF_T *size);
+
+
+/**
+ * Creates an interprocess channel
+ *
+ * @param blocking_read creates an asynchronous pipe for reading if set to GNUNET_NO
+ * @param blocking_write creates an asynchronous pipe for writing if set to GNUNET_NO
+ * @param inherit_read 1 to make read handle inheritable, 0 otherwise (NT only)
+ * @param inherit_write 1 to make write handle inheritable, 0 otherwise (NT only)
+ * @return handle to the new pipe, NULL on error
+ */
+struct GNUNET_DISK_PipeHandle *
+GNUNET_DISK_pipe (int blocking_read, int blocking_write, int inherit_read, int inherit_write);
+
+
+/**
+ * Creates a pipe object from a couple of file descriptors.
+ * Useful for wrapping existing pipe FDs.
+ *
+ * @param blocking_read creates an asynchronous pipe for reading if set to GNUNET_NO
+ * @param blocking_write creates an asynchronous pipe for writing if set to GNUNET_NO
+ * @param fd an array of two fd values. One of them may be -1 for read-only or write-only pipes
+ *
+ * @return handle to the new pipe, NULL on error
+ */
+struct GNUNET_DISK_PipeHandle *
+GNUNET_DISK_pipe_from_fd (int blocking_read, int blocking_write, int fd[2]);
+
+/**
+ * Closes an interprocess channel
+ * @param p pipe
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
+
+/**
+ * Closes one half of an interprocess channel
+ *
+ * @param p pipe to close end of
+ * @param end which end of the pipe to close
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_pipe_close_end (struct GNUNET_DISK_PipeHandle *p,
+                            enum GNUNET_DISK_PipeEnd end);
+
+/**
+ * Close an open file.
+ *
+ * @param h file handle
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
+
+
+/**
+ * Get the handle to a particular pipe end
+ *
+ * @param p pipe
+ * @param n end to access
+ * @return handle for the respective end
+ */
+const struct GNUNET_DISK_FileHandle *
+GNUNET_DISK_pipe_handle (const struct GNUNET_DISK_PipeHandle *p,
+                         enum GNUNET_DISK_PipeEnd n);
+
+/**
+ * Read the contents of a binary file into a buffer.
+ * @param h handle to an open file
+ * @param result the buffer to write the result to
+ * @param len the maximum number of bytes to read
+ * @return the number of bytes read on success, GNUNET_SYSERR on failure
+ */
+ssize_t
+GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h, void *result,
+                       size_t len);
+
+/**
+ * Read the contents of a binary file into a buffer.
+ * Guarantees not to block (returns GNUNET_SYSERR and sets errno to EAGAIN
+ * when no data can be read).
+ *
+ * @param h handle to an open file
+ * @param result the buffer to write the result to
+ * @param len the maximum number of bytes to read
+ * @return the number of bytes read on success, GNUNET_SYSERR on failure
+ */
+ssize_t
+GNUNET_DISK_file_read_non_blocking (const struct GNUNET_DISK_FileHandle * h,
+    void *result, size_t len);
+
+/**
+ * Read the contents of a binary file into a buffer.
+ *
+ * @param fn file name
+ * @param result the buffer to write the result to
+ * @param len the maximum number of bytes to read
+ * @return number of bytes read, GNUNET_SYSERR on failure
+ */
+ssize_t
+GNUNET_DISK_fn_read (const char *fn, void *result, size_t len);
+
+
+/**
+ * Write a buffer to a file.
+ *
+ * @param h handle to open file
+ * @param buffer the data to write
+ * @param n number of bytes to write
+ * @return number of bytes written on success, GNUNET_SYSERR on error
+ */
+ssize_t
+GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
+                        const void *buffer, size_t n);
+
+
+/**
+ * Write a buffer to a file, blocking, if necessary.
+ * @param h handle to open file
+ * @param buffer the data to write
+ * @param n number of bytes to write
+ * @return number of bytes written on success, GNUNET_SYSERR on error
+ */
+ssize_t
+GNUNET_DISK_file_write_blocking (const struct GNUNET_DISK_FileHandle * h,
+    const void *buffer, size_t n);
+
+/**
+ * Write a buffer to a file.  If the file is longer than
+ * the given buffer size, it will be truncated.
+ *
+ * @param fn file name
+ * @param buffer the data to write
+ * @param n number of bytes to write
+ * @param mode file permissions
+ * @return number of bytes written on success, GNUNET_SYSERR on error
+ */
+ssize_t
+GNUNET_DISK_fn_write (const char *fn, const void *buffer, size_t n,
+                      enum GNUNET_DISK_AccessPermissions mode);
+
+
+/**
+ * Copy a file.
+ *
+ * @param src file to copy
+ * @param dst destination file name
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_file_copy (const char *src, const char *dst);
+
+
+/**
+ * Scan a directory for files.
+ *
+ * @param dirName the name of the directory
+ * @param callback the method to call for each file
+ * @param callback_cls closure for callback
+ * @return the number of files found, -1 on error
+ */
+int
+GNUNET_DISK_directory_scan (const char *dirName,
+                            GNUNET_FileNameCallback callback,
+                            void *callback_cls);
+
+
+/**
+ * Opaque handle used for iterating over a directory.
+ */
+struct GNUNET_DISK_DirectoryIterator;
+
+
+/**
+ * Function called to iterate over a directory.
+ *
+ * @param cls closure
+ * @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
+ *           get called on the next entry (or finish cleanly);
+ *           NULL on error (will be the last call in that case)
+ * @param filename complete filename (absolute path)
+ * @param dirname directory name (absolute path)
+ */
+typedef void (*GNUNET_DISK_DirectoryIteratorCallback) (void *cls,
+                                                       struct
+                                                       GNUNET_DISK_DirectoryIterator
+                                                       * di,
+                                                       const char *filename,
+                                                       const char *dirname);
+
+
+/**
+ * This function must be called during the DiskIteratorCallback
+ * (exactly once) to schedule the task to process the next
+ * filename in the directory (if there is one).
+ *
+ * @param iter opaque handle for the iterator
+ * @param can set to GNUNET_YES to terminate the iteration early
+ * @return GNUNET_YES if iteration will continue,
+ *         GNUNET_NO if this was the last entry (and iteration is complete),
+ *         GNUNET_SYSERR if "can" was YES
+ */
+int
+GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator *iter,
+                                     int can);
+
+
+/**
+ * Scan a directory for files using the scheduler to run a task for
+ * each entry.  The name of the directory must be expanded first (!).
+ * If a scheduler does not need to be used, GNUNET_DISK_directory_scan
+ * may provide a simpler API.
+ *
+ * @param prio priority to use
+ * @param dirName the name of the directory
+ * @param callback the method to call for each file
+ * @param callback_cls closure for callback
+ * @return GNUNET_YES if directory is not empty and 'callback'
+ *         will be called later, GNUNET_NO otherwise, GNUNET_SYSERR on error.
+ */
+int
+GNUNET_DISK_directory_iterator_start (enum GNUNET_SCHEDULER_Priority prio,
+                                      const char *dirName,
+                                      GNUNET_DISK_DirectoryIteratorCallback
+                                      callback, void *callback_cls);
+
+
+/**
+ * Create the directory structure for storing
+ * a file.
+ *
+ * @param filename name of a file in the directory
+ * @returns GNUNET_OK on success, GNUNET_SYSERR on failure,
+ *          GNUNET_NO if directory exists but is not writeable
+ */
+int
+GNUNET_DISK_directory_create_for_file (const char *filename);
+
+
+/**
+ * Test if "fil" is a directory that can be accessed.
+ * Will not print an error message if the directory
+ * does not exist.  Will log errors if GNUNET_SYSERR is
+ * returned.
+ *
+ * @param fil filename to test
+ * @return GNUNET_YES if yes, GNUNET_NO if does not exist, GNUNET_SYSERR
+ *   on any error and if exists but not directory
+ */
+int
+GNUNET_DISK_directory_test (const char *fil);
+
+
+/**
+ * Remove all files in a directory (rm -rf). Call with
+ * caution.
+ *
+ * @param fileName the file to remove
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_directory_remove (const char *fileName);
+
+
+/**
+ * Implementation of "mkdir -p"
+ *
+ * @param dir the directory to create
+ * @returns GNUNET_SYSERR on failure, GNUNET_OK otherwise
+ */
+int
+GNUNET_DISK_directory_create (const char *dir);
+
+
+/**
+ * Lock a part of a file.
+ *
+ * @param fh file handle
+ * @param lockStart absolute position from where to lock
+ * @param lockEnd absolute position until where to lock
+ * @param excl GNUNET_YES for an exclusive lock
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_file_lock (struct GNUNET_DISK_FileHandle *fh, OFF_T lockStart,
+                       OFF_T lockEnd, int excl);
+
+
+/**
+ * Unlock a part of a file
+ * @param fh file handle
+ * @param unlockStart absolute position from where to unlock
+ * @param unlockEnd absolute position until where to unlock
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DISK_file_unlock (struct GNUNET_DISK_FileHandle *fh, OFF_T unlockStart,
+                         OFF_T unlockEnd);
+
+
+/**
+ * @brief Removes special characters as ':' from a filename.
+ * @param fn the filename to canonicalize
+ */
+void
+GNUNET_DISK_filename_canonicalize (char *fn);
+
+
+/**
+ * @brief Change owner of a file
+ * @param filename file to change
+ * @param user new owner of the file
+ * @return GNUNET_OK on success, GNUNET_SYSERR on failure
+ */
+int
+GNUNET_DISK_file_change_owner (const char *filename, const char *user);
+
+
+/**
+ * Construct full path to a file inside of the private
+ * directory used by GNUnet.  Also creates the corresponding
+ * directory.  If the resulting name is supposed to be
+ * a directory, end the last argument in '/' (or pass
+ * DIR_SEPARATOR_STR as the last argument before NULL).
+ *
+ * @param cfg configuration to use
+ * @param serviceName name of the service asking
+ * @param ... is NULL-terminated list of
+ *                path components to append to the
+ *                private directory name.
+ * @return the constructed filename
+ */
+char *
+GNUNET_DISK_get_home_filename (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                               const char *serviceName, ...);
+
+
+/**
+ * Opaque handle for a memory-mapping operation.
+ */
+struct GNUNET_DISK_MapHandle;
+
+/**
+ * Map a file into memory
+ * @param h open file handle
+ * @param m handle to the new mapping (will be set)
+ * @param access access specification, GNUNET_DISK_MAP_TYPE_xxx
+ * @param len size of the mapping
+ * @return pointer to the mapped memory region, NULL on failure
+ */
+void *
+GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
+                      struct GNUNET_DISK_MapHandle **m,
+                      enum GNUNET_DISK_MapType access, size_t len);
+
+/**
+ * Unmap a file
+ *
+ * @param h mapping handle
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
+
+/**
+ * Write file changes to disk
+ * @param h handle to an open file
+ * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
+ */
+int
+GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
+
+
+#if 0                           /* keep Emacsens' auto-indent happy */
+{
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+
+/* ifndef GNUNET_DISK_LIB_H */
+#endif
+/* end of gnunet_disk_lib.h */