[Extractor-gtk-cvslog] SF.net SVN: extractor-gtk:[97] trunk/extractor/generic.c

[<som...@us...>]

Revision: 97
          http://extractor-gtk.svn.sourceforge.net/extractor-gtk/?rev=97&view=rev
Author:   someone-guy
Date:     2008-08-22 16:08:44 +0000 (Fri, 22 Aug 2008)

Log Message:
-----------
Optimize generic file parsing.

Modified Paths:
--------------
    trunk/extractor/generic.c

Modified: trunk/extractor/generic.c
===================================================================
--- trunk/extractor/generic.c	2008-08-22 16:08:20 UTC (rev 96)
+++ trunk/extractor/generic.c	2008-08-22 16:08:44 UTC (rev 97)
@@ -31,56 +31,99 @@
 
 typedef uint64_t buffer_t;
 
+#define RAMBUF_SZ (256 * 1024)
+
+static inline uint16_t get_le16(uint8_t **p) {
+  uint16_t res = *(*p)++;
+  res += *(*p)++ << 8;
+  return res;
+}
+
+static inline uint16_t get_be16(uint8_t **p) {
+  uint16_t res = *(*p)++ << 8;
+  res += *(*p)++;
+  return res;
+}
+
+static inline uint32_t get_le32(uint8_t **p) {
+  uint32_t res = get_le16(p);
+  res += get_le16(p) << 16;
+  return res;
+}
+
+static inline uint32_t get_be32(uint8_t **p) {
+  uint32_t res = get_be16(p) << 16;
+  res += get_be16(p);
+  return res;
+}
+
 static file_t *get_list(FILE *in) {
   register buffer_t t = 0;
+  uint8_t *rambuf = malloc(2 * RAMBUF_SZ);
+  uint64_t fpos = 0;
+  int rambuf_used = 0;
+  int rambuf_pos = 0;
   int bz2idx = -1;
   int pngidx = -1;
   int cnt = 0;
   file_t *list = calloc(1, sizeof(file_t));
-  rewind(in);
-  while (!feof(in) && cnt < MAX_FILES) {
+  while (cnt < MAX_FILES) {
+    uint8_t *p;
     int i;
-    t = t << 8 | fgetc(in);
+    if (rambuf_pos >= rambuf_used || rambuf_pos >= RAMBUF_SZ) {
+      if (rambuf_pos >= RAMBUF_SZ) {
+        rambuf_pos -= RAMBUF_SZ;
+        rambuf_used -= RAMBUF_SZ;
+        memcpy(rambuf, rambuf + RAMBUF_SZ, RAMBUF_SZ);
+      } else {
+        rambuf_pos = rambuf_used = 0;
+      }
+      rambuf_used += fread(rambuf + rambuf_used, 1, 2 * RAMBUF_SZ - rambuf_used, in);
+      if (rambuf_used <= 0) break; // EOF
+    }
+    t = t << 8 | rambuf[rambuf_pos++];
+    p = rambuf + rambuf_pos;
+    fpos++;
     switch (t) {
       case HUGETAG(0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1, 0x1a, 0xe1):
         add_entry(&list, cnt, "msi");
-        list[cnt].start = ftell(in) - 8;
+        list[cnt].start = fpos - 8;
         cnt++;
         break;
       case HUGETAG(0x89, 'P', 'N', 'G', 0x0d, 0x0a, 0x1a, 0x0a):
         if (pngidx >= 0 && list[pngidx].len == 0)
-          list[pngidx].len = ftell(in) - list[pngidx].start - 8;
+          list[pngidx].len = fpos - list[pngidx].start - 8;
         add_entry(&list, cnt, "png");
-        list[cnt].start = ftell(in) - 8;
+        list[cnt].start = fpos - 8;
         pngidx = cnt;
         cnt++;
         break;
       case HUGETAG(0, 0, 0, 0, 'I', 'E', 'N', 'D'):
         if (pngidx >= 0)
-          list[pngidx].len = ftell(in) - list[pngidx].start + 4;
+          list[pngidx].len = fpos - list[pngidx].start + 4;
         break;
     }
-    switch (t & 0xffffffff) {
+    switch ((uint32_t)t) {
       case TAG('M', 'S', 'C', 'F'): {
-        uint32_t unk = read_le32(in);
-        uint32_t size = read_le32(in);
-        fseek(in, -8, SEEK_CUR);
+        uint32_t unk = get_le32(&p);
+        uint32_t size = get_le32(&p);
+        p -= 8;
         add_entry(&list, cnt, "cab");
-        list[cnt].start = ftell(in) - 4;
+        list[cnt].start = fpos - 4;
         list[cnt].len = size;
         cnt++;
         break;
       }
       case TAG('R', 'I', 'F', 'F'): {
         const char *ext = "riff";
-        uint32_t len = read_le32(in);
-        uint32_t type = read_be32(in);
-        fseek(in, -8, SEEK_CUR);
+        uint32_t len = get_le32(&p);
+        uint32_t type = get_be32(&p);
+        p -= 8;
         if (len <= 4 || !is_valid_fourcc(type)) break;
         if (type == TAG('W', 'A', 'V', 'E')) ext = "wav";
         if (type >> 8 == TAG(0, 'A', 'V', 'I')) ext = "avi";
         add_entry(&list, cnt, ext);
-        list[cnt].start = ftell(in) - 4;
+        list[cnt].start = fpos - 4;
         list[cnt].len = len + 8;
         cnt++;
         break;
@@ -88,16 +131,16 @@
       case TAG('P', 'K', 5, 6): {
         uint64_t offset;
         uint16_t comment_len;
-        fseek(in, 8, SEEK_CUR);
-        offset = read_le32(in); // size of central directory
-        offset += read_le32(in); // offset of central directory
+        p += 8;
+        offset = get_le32(&p); // size of central directory
+        offset += get_le32(&p); // offset of central directory
         offset += 4; // PK..
-        comment_len = read_le16(in); // comment length
-        fseek(in, -18, SEEK_CUR);
-        if (offset > ftell(in))
+        comment_len = get_le16(&p); // comment length
+        p -= 18;
+        if (offset > fpos)
           break;
         add_entry(&list, cnt, "zip");
-        list[cnt].start = ftell(in) - offset;
+        list[cnt].start = fpos - offset;
         list[cnt].len = offset + 18 + comment_len;
         cnt++;
       }
@@ -107,49 +150,49 @@
       // compressed flash. Note that length is _decompressed_ size
       // so we will extract more data than necessary
       case TAG(0, 'C', 'W', 'S'): {
-        uint8_t ver = fgetc(in);
-        uint32_t size = read_le32(in);
-        uint8_t rectbits = fgetc(in) >> 3;
-        fseek(in, -6, SEEK_CUR);
+        uint8_t ver = *p++;
+        uint32_t size = get_le32(&p);
+        uint8_t rectbits = *p++ >> 3;
+        p -= 6;
         if ((ver & 0xf0) || rectbits != 15)
           break;
         add_entry(&list, cnt, "swf");
-        list[cnt].start = ftell(in) - 3;
+        list[cnt].start = fpos - 3;
         list[cnt].len = size;
         cnt++;
         break;
       }
       case TAG(0, 'B', 'Z', 'h'):
         if (bz2idx >= 0 && list[bz2idx].len == 0) {
-          list[bz2idx].start = ftell(in) - 3;
+          list[bz2idx].start = fpos - 3;
           break;
         }
         add_entry(&list, cnt, "bz2");
-        list[cnt].start = ftell(in) - 3;
+        list[cnt].start = fpos - 3;
         bz2idx = cnt;
         cnt++;
         break;
       case 0xffd8ff:
         add_entry(&list, cnt, "jpg");
-        list[cnt].start = ftell(in) - 3;
+        list[cnt].start = fpos - 3;
         list[cnt].priv = (void *)1;
         cnt++;
         break;
     }
-    switch (t & 0xffff) {
+    switch ((uint16_t)t) {
       case TAG(0, 0, 'B', 'M'): {
-        uint32_t len = read_le32(in);
-        uint16_t res1 = read_le16(in);
-        uint16_t res2 = read_le16(in);
-        uint32_t dataoff = read_le32(in);
-        uint32_t bisize = read_le32(in);
-        fseek(in, -16, SEEK_CUR);
+        uint32_t len = get_le32(&p);
+        uint16_t res1 = get_le16(&p);
+        uint16_t res2 = get_le16(&p);
+        uint32_t dataoff = get_le32(&p);
+        uint32_t bisize = get_le32(&p);
+        p -= 16;
         if (bisize < 40 || bisize > 1024*1024 ||
             dataoff < bisize + 14 || len < dataoff ||
             len > 1024*1024*1024)
           break;
         add_entry(&list, cnt, "bmp");
-        list[cnt].start = ftell(in) - 2;
+        list[cnt].start = fpos - 2;
         list[cnt].len = len;
         cnt++;
         break;
@@ -157,7 +200,7 @@
       case 0xffd9:
         for (i = 0; i < cnt; i++) {
           if (list[i].priv == (void *)1 && list[i].len == 0)
-            list[i].len = ftell(in) - list[i].start;
+            list[i].len = fpos - list[i].start;
         }
         break;
     }
@@ -166,17 +209,19 @@
       // if buffer_t is changed to only 32 bits, otherwise all 48 bits
       buffer_t endmark = 0x177245385090ULL;
       buffer_t mask = 0xffffffffffffULL;
-      for (i = 0; i < 8; i++) {
+      i = 8;
+      do {
         if ((t & mask) == endmark) {
           // end marker plus space for CRC
-          list[bz2idx].len = ftell(in) - list[bz2idx].start + 4;
+          list[bz2idx].len = fpos - list[bz2idx].start + 4;
           break;
         }
         endmark <<= 1;
         mask <<= 1;
-      }
+      } while (--i);
     }
   }
+  free(rambuf);
   return list;
 }
 


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