--- file.h.orig 2013-01-30 20:16:01 UTC
+++ file.h
@@ -3,6 +3,7 @@
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <stdio.h>
+#include <cstdlib>
#define MAX_IO_BLOCK_SIZE (1024 * 1024)
@@ -58,6 +59,44 @@ unsigned read_dword(FILE *f) {
return (read_word(f) << 16) + low;
}
+static size_t scan_varint(const char* in,size_t len, unsigned long long* n) {
+ size_t i;
+ unsigned long long l;
+ if (len==0) return 0;
+ for (l=0, i=0; i<len; ++i) {
+ l+=(unsigned long long)(in[i]&0x7f) << (i*7);
+ if (!(in[i]&0x80)) {
+ *n=l;
+ return i+1;
+ }
+ }
+ return 0;
+}
+
+size_t scan_pb_type0_sint(const char* in,size_t len,signed long long* l) {
+ unsigned long long m;
+ size_t n=scan_varint(in,len,&m);
+ if (!n) return 0;
+ *l=(-(m&1)) ^ (m>>1);
+ return n;
+}
+
+long long read_varint(FILE* f) {
+ char buf[20];
+ size_t i;
+ long long l;
+ for (i=0; i<sizeof(buf); ++i) {
+ fread_fixed(f,buf+i,1);
+ if (!(buf[i]&0x80)) {
+ if (scan_pb_type0_sint(buf,i+1,&l)!=i+1) break;
+ return l;
+ }
+ }
+ static char read_error_message[128];
+ strcpy(read_error_message, "parse error: read_varint() failed");
+ throw read_error_message;
+}
+
void write_word(FILE *f, unsigned number) {
unsigned char b = number & 255,
b2 = number >> 8;
@@ -70,6 +109,31 @@ void write_dword(FILE *f, unsigned numbe
write_word(f, number >> 16);
}
+
+/* write int in least amount of bytes, return number of bytes */
+/* as used in varints from Google protocol buffers */
+static size_t fmt_varint(char* dest,unsigned long long l) {
+ /* high bit says if more bytes are coming, lower 7 bits are payload; little endian */
+ size_t i;
+ for (i=0; l; ++i, l>>=7) {
+ if (dest) dest[i]=(l&0x7f) | ((!!(l&~0x7f))<<7);
+ }
+ if (!i) { /* l was 0 */
+ if (dest) dest[0]=0;
+ ++i;
+ }
+ return i;
+}
+
+static size_t fmt_pb_type0_sint(char* dest,signed long long l) {
+ return fmt_varint(dest,(l << 1) ^ (l >> (sizeof(l)*8-1)));
+}
+
+void write_varint(FILE* f, long long number) {
+ char tmp[20];
+ fwrite_fixed(f,tmp,fmt_pb_type0_sint(tmp,number));
+}
+
bool fileExists(char *fname) {
FILE *f = fopen(fname, "rb");
bool exists = (f != NULL);
