guac_message structure, initial parsing support

guacamole/proxy/protocol.c

@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <errno.h>
 #include <png.h>
 
 #include "guacio.h"
@@ -175,3 +176,98 @@ void guac_send_png(GUACIO* io, int x, int y, png_byte** png_rows, int w, int h)
 }
 
 
+int __guac_fill_messagebuf(GUACIO* io) {
+
+    int retval;
+    
+    /* Attempt to fill buffer */
+    retval = read(
+            io->fd,
+            io->messagebuf + io->messagebuf_used_length,
+            io->messagebuf_size - io->messagebuf_used_length
+    );
+
+    if (retval < 0)
+        return retval;
+
+    io->messagebuf_used_length += retval;
+
+    /* Expand buffer if necessary */
+    if (io->messagebuf_used_length > io->messagebuf_size / 2) {
+        io->messagebuf_size *= 2;
+        io->messagebuf = realloc(io->messagebuf, io->messagebuf_size);
+    }
+
+    return retval;
+
+}
+
+guac_message* guac_read_message(GUACIO* io) {
+
+    guac_message* parsed_message;
+    int retval;
+    int i = 0;
+    
+    /* Loop until a message is read */
+    for (;;) {
+
+        /* Search for end of message */
+        for (; i < io->messagebuf_used_length; i++) {
+
+            if (io->messagebuf[i] == ';') {
+
+                /* Parse new message */
+                char* message = malloc(i+1);
+                memcpy(message, io->messagebuf, i+1);
+                message[i] = '\0'; /* Replace semicolon with null terminator. */
+
+                parsed_message = malloc(sizeof(guac_message));
+                parsed_message->opcode = message;
+                parsed_message->argc = 0;
+                parsed_message->argv = NULL;
+
+                /* Found. Reset buffer */
+                memmove(io->messagebuf, io->messagebuf + i + 1, io->messagebuf_used_length - i - 1);
+                io->messagebuf_used_length -= i + 1;
+
+                /* Done */
+                return parsed_message;
+            }
+
+        }
+
+        /* No message yet? Get more data ... */
+        retval = guac_select(io, 1000);
+        if (retval < 0)
+            return NULL;
+
+        /* Break if descriptor doesn't have enough data */
+        if (retval == 0)
+            return NULL; /* SOFT FAIL: No message ... yet, but is still in buffer */
+
+        retval = __guac_fill_messagebuf(io);
+        if (retval < 0 && errno != EAGAIN && errno != EWOULDBLOCK)
+            return NULL;
+
+    }
+
+}
+
+void guac_free_message(guac_message* message) {
+    free(message->opcode);
+
+    if (message->argv)
+        free(message->argv);
+
+    free(message);
+}
+
+
+int guac_messages_waiting(GUACIO* io) {
+
+    if (io->messagebuf_used_length > 0)
+        return 1;
+
+    return guac_select(io, 1000);
+}
+