Do some io and hostlist fetching.

4 files changed, 33 insertions, 0 deletions

diff --git a/src/org/gnu/clojure/gnunet/hostlist.clj b/src/org/gnu/clojure/gnunet/hostlist.clj
new file mode 100644
index 0000000..f1e20cb
--- /dev/null
+++ b/src/org/gnu/clojure/gnunet/hostlist.clj
@@ -0,0 +1,11 @@
+(ns org.gnu.clojure.gnunet.hostlist
+  (:use (org.gnu.clojure.gnunet parser message hello iostream)))
+
+(defn download-hostlist
+  "Calls the hello-processor on all parsed hello messages at the given URL."
+  [url hello-processor]
+  (doseq [msg (first ((none-or-more parse-message) (read-url url)))
+        :while (== (:message-type msg) message-type-hello)]
+    (try
+      (hello-processor (first (parse-hello (:bytes msg))))
+      (catch Exception e nil))))
diff --git a/src/org/gnu/clojure/gnunet/iostream.clj b/src/org/gnu/clojure/gnunet/iostream.clj
new file mode 100644
index 0000000..b4cb066
--- /dev/null
+++ b/src/org/gnu/clojure/gnunet/iostream.clj
@@ -0,0 +1,14 @@
+(ns org.gnu.clojure.gnunet.iostream
+  (:import java.net.URL))
+
+(defn reader
+  "Converts a java.io.InputStream into a lazy seq of bytes."
+  [in]
+  (lazy-seq (let [c (.read in)] (when (>= c 0) (cons (byte c) (reader in))))))
+
+(defn read-url
+  "Open a URL and return a seq of its data."
+  [url]
+  (try
+    (reader (.openStream (URL. url)))
+    (catch Exception e nil)))
diff --git a/src/org/gnu/clojure/gnunet/message.clj b/src/org/gnu/clojure/gnunet/message.clj
index 4c74b71..6deca23 100644
--- a/src/org/gnu/clojure/gnunet/message.clj
+++ b/src/org/gnu/clojure/gnunet/message.clj
@@ -50,6 +50,7 @@
   (domonad parser-m [xs (items 8)] (decode-uint xs)))
 
 (defn encode-utf8
+  "Converts a string into a null-terminated sequence of bytes in UTF-8."
   [string]
   (concat
     (.getBytes string "UTF-8")
@@ -88,3 +89,9 @@
   (concat
     (encode-header (+ (count (:bytes msg)) header-size) (:message-type msg))
     (:bytes msg)))
+
+(def parse-message
+  (domonad parser-m [header parse-header
+                     message (items (- (:size header) header-size))]
+    {:message-type (:message-type header)
+     :bytes message}))
diff --git a/src/org/gnu/clojure/gnunet/parser.clj b/src/org/gnu/clojure/gnunet/parser.clj
index 73ecd86..a0ba7c3 100644
--- a/src/org/gnu/clojure/gnunet/parser.clj
+++ b/src/org/gnu/clojure/gnunet/parser.clj
@@ -18,6 +18,7 @@
         (cons x xs)))))
 
 (defn is
+  "Produces a parser that matches an item which satisfies the given predicate."
   [p]
   (domonad parser-m [x item
                      :when (p x)]