Implemented initial MQTT interface

1 files changed, 221 insertions, 0 deletions

diff --git a/facebook/facebook-util.c b/facebook/facebook-util.c
index 84cc581..5cea807 100644
--- a/facebook/facebook-util.c
+++ b/facebook/facebook-util.c
@@ -15,7 +15,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <stdarg.h>
 #include <string.h>
+#include <zlib.h>
 
 #include "facebook-util.h"
 
@@ -41,6 +43,80 @@ gboolean fb_util_debugging(void)
 #endif /* DEBUG_FACEBOOK */
 
 /**
+ * Dumps a #GByteArray to the debugging stream. This formats the output
+ * similar to that of `hexdump -C`.
+ *
+ * @param bytes  The #GByteArray.
+ * @param indent The indent width.
+ * @param fmt    The format string or NULL.
+ * @param ...    The format arguments.
+ **/
+#ifdef DEBUG_FACEBOOK
+void fb_util_hexdump(const GByteArray *bytes, guint indent,
+                     const gchar *fmt, ...)
+{
+    GString *gstr;
+    va_list  ap;
+    gchar   *instr;
+    guint    i;
+    guint    j;
+    gchar    c;
+
+    if (fmt != NULL) {
+        va_start(ap, fmt);
+        instr = g_strdup_vprintf(fmt, ap);
+        FB_UTIL_DEBUGLN("%s", instr);
+        g_free(instr);
+        va_end(ap);
+    }
+
+    instr = g_strnfill(indent, ' ');
+    gstr  = g_string_sized_new(80);
+    i     = 0;
+
+    if (G_UNLIKELY(bytes == NULL))
+        goto finish;
+
+    for (; i < bytes->len; i += 16) {
+        g_string_append_printf(gstr, "%s%08x  ", instr, i);
+
+        for (j = 0; j < 16; j++) {
+            if ((i + j) < bytes->len) {
+                g_string_append_printf(gstr, "%02x ", bytes->data[i + j]);
+            } else {
+                g_string_append(gstr, "   ");
+            }
+
+            if (j == 7)
+                g_string_append_c(gstr, ' ');
+        }
+
+        g_string_append(gstr, " |");
+
+        for (j = 0; (j < 16) && ((i + j) < bytes->len); j++) {
+            c = bytes->data[i + j];
+
+            if (!g_ascii_isprint(c) || g_ascii_isspace(c))
+                c = '.';
+
+            g_string_append_c(gstr, c);
+        }
+
+        g_string_append_c(gstr, '|');
+        FB_UTIL_DEBUGLN("%s", gstr->str);
+        g_string_erase(gstr, 0, -1);
+    }
+
+finish:
+    g_string_append_printf(gstr, "%s%08x", instr, i);
+    FB_UTIL_DEBUGLN("%s", gstr->str);
+
+    g_string_free(gstr, TRUE);
+    g_free(instr);
+}
+#endif /* DEBUG_FACEBOOK */
+
+/**
  * Compare two strings case insensitively. This is useful for where
  * the return value must be a boolean, such as with a #GEqualFunc.
  *
@@ -53,3 +129,148 @@ gboolean fb_util_str_iequal(const gchar *s1, const gchar *s2)
 {
     return g_ascii_strcasecmp(s1, s2) == 0;
 }
+
+/**
+ * Implemented #alloc_func for #g_malloc().
+ *
+ * @param opaque The user-defined data, which is NULL.
+ * @param items  The number of items.
+ * @param size   The size of each item.
+ *
+ * @return The pointer to the allocated memory.
+ **/
+static voidpf fb_util_zalloc(voidpf opaque, uInt items, uInt size)
+{
+    return g_malloc(size * items);
+}
+
+/**
+ * Implemented #free_func for #g_free().
+ *
+ * @param opaque  The user-defined data, which is NULL.
+ * @param address The pointer address.
+ **/
+static void fb_util_zfree(voidpf opaque, voidpf address)
+{
+    g_free(address);
+}
+
+/**
+ * Determines if a #GByteArray is zlib compressed.
+ *
+ * @param bytes The #GByteArray.
+ *
+ * @return TRUE if the #GByteArray is compressed, otherwise FALSE.
+ **/
+gboolean fb_util_zcompressed(const GByteArray *bytes)
+{
+    guint8 b0;
+    guint8 b1;
+
+    g_return_if_fail(bytes != NULL);
+
+    if (bytes->len < 2)
+        return FALSE;
+
+    b0 = *(bytes->data + 0);
+    b1 = *(bytes->data + 1);
+
+    return ((((b0 << 8) | b1) % 31) == 0) && /* Check the header */
+           ((b0 & 0x0F) == Z_DEFLATED);      /* Check the method */
+}
+
+/**
+ * Compresses a #GByteArray with zlib. The returned #GByteArray should
+ * be freed with #g_byte_array_free() when no longer needed.
+ *
+ * @param bytes The #GByteArray.
+ *
+ * @return The resulting #GByteArray, or NULL on error.
+ **/
+GByteArray *fb_util_zcompress(const GByteArray *bytes)
+{
+    GByteArray *ret;
+    z_stream    zs;
+    gsize       size;
+    gint        res;
+
+    g_return_if_fail(bytes != NULL);
+
+    memset(&zs, 0, sizeof zs);
+    zs.zalloc   = fb_util_zalloc;
+    zs.zfree    = fb_util_zfree;
+    zs.next_in  = bytes->data;
+    zs.avail_in = bytes->len;
+
+    if (deflateInit(&zs, Z_BEST_COMPRESSION) != Z_OK)
+        return NULL;
+
+    size = compressBound(bytes->len);
+    ret  = g_byte_array_new();
+
+    g_byte_array_set_size(ret, size);
+
+    zs.next_out  = ret->data;
+    zs.avail_out = size;
+
+    res = deflate(&zs, Z_FINISH);
+
+    if (res != Z_STREAM_END) {
+        deflateEnd(&zs);
+        g_byte_array_free(ret, TRUE);
+        return NULL;
+    }
+
+    size -= zs.avail_out;
+    g_byte_array_remove_range(ret, size, ret->len - size);
+
+    deflateEnd(&zs);
+    return ret;
+}
+
+/**
+ * Uncompresses a zlib compressed #GByteArray. The returned #GByteArray
+ * should be freed with #g_byte_array_free() when no longer needed.
+ *
+ * @param bytes The #GByteArray.
+ *
+ * @return The resulting #GByteArray, or NULL on error.
+ **/
+GByteArray *fb_util_zuncompress(const GByteArray *bytes)
+{
+    GByteArray *ret;
+    z_stream    zs;
+    guint8      out[1024];
+    gint        res;
+
+    g_return_if_fail(bytes != NULL);
+
+    memset(&zs, 0, sizeof zs);
+    zs.zalloc   = fb_util_zalloc;
+    zs.zfree    = fb_util_zfree;
+    zs.next_in  = bytes->data;
+    zs.avail_in = bytes->len;
+
+    if (inflateInit(&zs) != Z_OK)
+        return NULL;
+
+    ret = g_byte_array_new();
+
+    do {
+        zs.next_out  = out;
+        zs.avail_out = sizeof out;
+
+        res = inflate(&zs, Z_NO_FLUSH);
+
+        if ((res != Z_OK) && (res != Z_STREAM_END)) {
+            inflateEnd(&zs);
+            g_byte_array_free(ret, TRUE);
+            return NULL;
+        }
+
+        g_byte_array_append(ret, out, sizeof out - zs.avail_out);
+    } while (res != Z_STREAM_END);
+
+    inflateEnd(&zs);
+    return ret;
+}