ss_bsdiff: Change the logic of timing out when creating deltas.

Patch is created with score = 8. If the action does not finish within 4
hours, the creation is aborted and started with score = 4 without
timeout.

Change-Id: I83f1d2cc356b419f81717d2983444d22e97d7b85

1 files changed, 9 insertions, 10 deletions

diff --git a/bsdiff/ss_bsdiff.c b/bsdiff/ss_bsdiff.c
index a01aa89..b153a73 100755
--- a/bsdiff/ss_bsdiff.c
+++ b/bsdiff/ss_bsdiff.c
@@ -57,7 +57,7 @@
 #define CONST_MEMORY_USAGE 16384		// patch in m+O(1); m=size of new file; use only const memory for old file at patch side;
 #define PATCH_FILE_FORMAT_MOD       // no accumulation of diff and extra in db and eb; immediate write; also write all 3 parts of control stmt at same time
 #define MULTI_THREADING 1            // only with #define CONST_MEMORY_USAGE or #define MAX_MATCH_SIZE
-#define TIME_LIMIT_CHECK 300		// After TIME_LIMIT_CHECK seconds, new diff will be created with smaller score argument
+#define TIME_LIMIT_CHECK 4*60*60	// After TIME_LIMIT_CHECK seconds, new diff will be created with smaller score argument
 #define TEMP_PATCH_NAME "temp_patch"
 #define BROTLI_COMPRESSION_QUALITY 9
 #define ITERATIONS_COMPLETED 10		// After ITERATIONS_COMPLETED iterations elapsed time will be checked. Increasing it can cause the program to run longer than expected
@@ -371,7 +371,7 @@ int Function(int offset_oldscore)
 						(data.old[scsc + lastoffset] == data.new[thread_num][scsc]))
 					oldscore++;
 #ifdef TIME_LIMIT_CHECK
-			if (offset_oldscore != 0) // when offset_oldscore is 0 we have to make sure diff is created no mater what, so we can't timeout 
+			if (offset_oldscore > 4) // when offset_oldscore is 4 and less we have to make sure diff is created no mater what, so we can't timeout
 				outer_count++;
 			if (outer_count > ITERATIONS_COMPLETED) {
 				outer_count = 0;
@@ -744,14 +744,13 @@ int MY_CDECL main(int argc, char *argv[])
 
 	int ret = create_patch(info.old_file, info.new_file, TEMP_PATCH_NAME, 8);
 #ifdef TIME_LIMIT_CHECK
-	/*
-	 * Creating a patch with an offset score equal to 8 may take too long. On
-	 * the other hand for a value of 2 the resulting patch will consist of
-	 * multiple blocks, which can significantly increase the application time.
-	 * Therefore this commit adds two intermediate steps as a compromise
-	 * solution.
-	*/
-	for (int score = 6; score >= 0 && ret != 0; score-=2) {
+	if (ret != 0) {
+		/*
+		 * Creating a patch with an offset score equal to 8 may take too long
+		 * Therefore after a certain amount of time, patch creation is aborted
+		 * and we run again with the score equal to 4.
+		 */
+		int score = 4;
 		printf("Trying with offset score %d\n", score);
 		ret = create_patch(info.old_file, info.new_file, TEMP_PATCH_NAME, score);
 	}