1 files changed, 82 insertions, 34 deletions
diff --git a/ext/metadata/metadatamuxpng.c b/ext/metadata/metadatamuxpng.c
index dd3828cd..728922aa 100644
--- a/ext/metadata/metadatamuxpng.c
+++ b/ext/metadata/metadatamuxpng.c
@@ -87,6 +87,87 @@
 #define READ(buf, size) ( (size)--, *((buf)++) )
 
 /*
+ * static global vars
+ */
+
+static const guint32 metadatamux_crc_table[256] = {
+  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+  0xe963a535,
+  0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b,
+  0x7eb17cbd,
+  0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+  0x1adad47d,
+  0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a,
+  0x8a65c9ec,
+  0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e,
+  0xd56041e4,
+  0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa,
+  0x42b2986c,
+  0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+  0x26d930ac,
+  0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
+  0xb8bda50f,
+  0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11,
+  0xc1611dab,
+  0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589,
+  0x06b6b51f,
+  0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
+  0x7f6a0dbb,
+  0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8,
+  0xf262004e,
+  0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+  0x8bbeb8ea,
+  0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158,
+  0x3ab551ce,
+  0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+  0x4369e96a,
+  0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f,
+  0xdd0d7cc9,
+  0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3,
+  0xb966d409,
+  0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
+  0x2eb40d81,
+  0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+  0xead54739,
+  0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e,
+  0x7a6a5aa8,
+  0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2,
+  0x1e01f268,
+  0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76,
+  0x89d32be0,
+  0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+  0xd6d6a3e8,
+  0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd,
+  0x48b2364b,
+  0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+  0x316e8eef,
+  0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795,
+  0xbb0b4703,
+  0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
+  0xc2d7ffa7,
+  0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
+  0x026d930a,
+  0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14,
+  0x7bb12bae,
+  0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4,
+  0xf1d4e242,
+  0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+  0x88085ae6,
+  0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3,
+  0x166ccf45,
+  0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
+  0x4969474d,
+  0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53,
+  0xdebb9ec5,
+  0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
+  0xbad03605,
+  0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02,
+  0x2a6f2b94,
+  0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+};
+
+
+/*
  * static helper functions declaration
  */
 
@@ -388,34 +469,6 @@ done:
 }
 
 /*
- * metadatamux_make_crc_table:
- * @crc_table: table to be written to.
- *
- * Creates a startup CRC table. For optimization it should be done only once.
- * @see_also: #metadatamux_update_crc
- *
- * Returns: nothing.
- */
-
-static void
-metadatamux_make_crc_table (guint32 crc_table[])
-{
-  guint32 c;
-  guint16 n, k;
-
-  for (n = 0; n < 256; n++) {
-    c = (guint32) n;
-    for (k = 0; k < 8; k++) {
-      if (c & 1)
-        c = 0xedb88320L ^ (c >> 1);
-      else
-        c = c >> 1;
-    }
-    crc_table[n] = c;
-  }
-}
-
-/*
  * metadatamux_update_crc:
  * @crc: seed to calculate the CRC
  * @buf: data to calculate the CRC for
@@ -432,14 +485,9 @@ metadatamux_update_crc (guint32 crc, guint8 * buf, guint32 len)
 {
   guint32 c = crc;
   guint32 n;
-  guint32 crc_table[256];
-
-  /* FIXME:  make_crc_table should be done once in life 
-     for speed up. It could be written hard coded to a file */
-  metadatamux_make_crc_table (crc_table);
 
   for (n = 0; n < len; n++) {
-    c = crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
+    c = metadatamux_crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
   }
   return c;
 }