Merge branch 'master' into next

[i3/i3] / libi3 / ipc_send_message.c

diff --git a/libi3/ipc_send_message.c b/libi3/ipc_send_message.c
index ff395adad0299d2cbd615ab246f7b36f1d436b2b..28cb8359207e128b648a664824b6dcc59950e07e 100644 (file)
--- a/libi3/ipc_send_message.c
+++ b/libi3/ipc_send_message.c
@@ -2,10 +2,7 @@
  * vim:ts=4:sw=4:expandtab
  *
  * i3 - an improved dynamic tiling window manager
- *
- * © 2009-2011 Michael Stapelberg and contributors
- *
- * See file LICENSE for license information.
+ * © 2009-2013 Michael Stapelberg and contributors (see also: LICENSE)
  *
  */
 #include <string.h>
@@ -13,9 +10,12 @@
 #include <unistd.h>
 #include <stdint.h>
 #include <err.h>
+#include <errno.h>
 
 #include <i3/ipc.h>
 
+#include "libi3.h"
+
 /*
  * Formats a message (payload) of the given size and type and sends it to i3 via
  * the given socket file descriptor.
@@ -24,29 +24,40 @@
  * Returns 0 on success.
  *
  */
-int ipc_send_message(int sockfd, uint32_t message_size,
-                     uint32_t message_type, const uint8_t *payload) {
-    int buffer_size = strlen(I3_IPC_MAGIC) + sizeof(uint32_t) + sizeof(uint32_t) + message_size;
-    char msg[buffer_size];
-    char *walk = msg;
-
-    strncpy(walk, I3_IPC_MAGIC, buffer_size - 1);
-    walk += strlen(I3_IPC_MAGIC);
-    memcpy(walk, &message_size, sizeof(uint32_t));
-    walk += sizeof(uint32_t);
-    memcpy(walk, &message_type, sizeof(uint32_t));
-    walk += sizeof(uint32_t);
-    memcpy(walk, payload, message_size);
-
-    int sent_bytes = 0;
-    int bytes_to_go = buffer_size;
-    while (sent_bytes < bytes_to_go) {
-        int n = write(sockfd, msg + sent_bytes, bytes_to_go);
-        if (n == -1)
+int ipc_send_message(int sockfd, const uint32_t message_size,
+                     const uint32_t message_type, const uint8_t *payload) {
+    const i3_ipc_header_t header = {
+        /* We don’t use I3_IPC_MAGIC because it’s a 0-terminated C string. */
+        .magic = {'i', '3', '-', 'i', 'p', 'c'},
+        .size = message_size,
+        .type = message_type};
+
+    size_t sent_bytes = 0;
+    int n = 0;
+
+    /* This first loop is basically unnecessary. No operating system has
+     * buffers which cannot fit 14 bytes into them, so the write() will only be
+     * called once. */
+    while (sent_bytes < sizeof(i3_ipc_header_t)) {
+        if ((n = write(sockfd, ((void *)&header) + sent_bytes, sizeof(i3_ipc_header_t) - sent_bytes)) == -1) {
+            if (errno == EAGAIN)
+                continue;
+            return -1;
+        }
+
+        sent_bytes += n;
+    }
+
+    sent_bytes = 0;
+
+    while (sent_bytes < message_size) {
+        if ((n = write(sockfd, payload + sent_bytes, message_size - sent_bytes)) == -1) {
+            if (errno == EAGAIN)
+                continue;
             return -1;
+        }
 
         sent_bytes += n;
-        bytes_to_go -= n;
     }
 
     return 0;