Merge "Support caching the suffix array."
diff --git a/bsdiff.cc b/bsdiff.cc
index 669a1e5..cb2ca7c 100644
--- a/bsdiff.cc
+++ b/bsdiff.cc
@@ -42,14 +42,6 @@
#include <algorithm>
-#if _FILE_OFFSET_BITS == 64
-#include "divsufsort64.h"
-#define saidx_t saidx64_t
-#define divsufsort divsufsort64
-#else
-#include "divsufsort.h"
-#endif
-
namespace bsdiff {
static off_t matchlen(const u_char* old, off_t oldsize, const u_char* new_buf,
@@ -135,7 +127,7 @@
(read(fd,new_buf,newsize)!=newsize) ||
(close(fd)==-1)) err(1,"%s",new_filename);
- int ret = bsdiff(old_buf, oldsize, new_buf, newsize, patch_filename);
+ int ret = bsdiff(old_buf, oldsize, new_buf, newsize, patch_filename, nullptr);
free(old_buf);
free(new_buf);
@@ -143,8 +135,12 @@
return ret;
}
+// Generate bsdiff patch from |old_buf| to |new_buf|, save the patch file to
+// |patch_filename|. Returns 0 on success.
+// |I_cache| can be used to cache the suffix array if the same |old_buf| is used
+// repeatedly, pass nullptr if not needed.
int bsdiff(const u_char* old_buf, off_t oldsize, const u_char* new_buf,
- off_t newsize, const char* patch_filename) {
+ off_t newsize, const char* patch_filename, saidx_t** I_cache) {
saidx_t *I;
off_t scan,pos=0,len;
off_t lastscan,lastpos,lastoffset;
@@ -160,10 +156,16 @@
BZFILE * pfbz2;
int bz2err;
- if((I=static_cast<saidx_t*>(malloc((oldsize+1)*sizeof(saidx_t))))==NULL)
- err(1,NULL);
+ if (I_cache && *I_cache) {
+ I = *I_cache;
+ } else {
+ if ((I=static_cast<saidx_t*>(malloc((oldsize+1)*sizeof(saidx_t))))==NULL)
+ err(1,NULL);
- if(divsufsort(old_buf, I, oldsize)) err(1, "divsufsort");
+ if (divsufsort(old_buf, I, oldsize)) err(1, "divsufsort");
+ if (I_cache)
+ *I_cache = I;
+ }
if(((db=static_cast<u_char*>(malloc(newsize+1)))==NULL) ||
((eb=static_cast<u_char*>(malloc(newsize+1)))==NULL)) err(1,NULL);
@@ -342,7 +344,8 @@
/* Free the memory we used */
free(db);
free(eb);
- free(I);
+ if (I_cache == nullptr)
+ free(I);
return 0;
}
diff --git a/bsdiff.h b/bsdiff.h
index 370ee03..7791777 100644
--- a/bsdiff.h
+++ b/bsdiff.h
@@ -7,6 +7,14 @@
#include <sys/types.h>
+#if _FILE_OFFSET_BITS == 64
+#include "divsufsort64.h"
+#define saidx_t saidx64_t
+#define divsufsort divsufsort64
+#else
+#include "divsufsort.h"
+#endif
+
namespace bsdiff {
int bsdiff(const char* old_filename,
@@ -17,7 +25,8 @@
off_t oldsize,
const u_char* new_buf,
off_t newsize,
- const char* patch_filename);
+ const char* patch_filename,
+ saidx_t** I_cache);
} // namespace bsdiff
