use struct strbuf instead of static buffers

Use "struct strbuf" from Git to remove the limit on file path length.

Notes on scan-tree:
This is slightly involved since I decided to pass the strbuf into
add_repo() and modify if whenever a new file name is required, which
should avoid any extra allocations within that function.  The pattern
there is to append the filename, use it and then reset the buffer to its
original length (retaining a trailing '/').

Notes on ui-snapshot:
Since write_archive modifies the argv array passed to it we
copy the argv_array values into a new array of char* and then free the
original argv_array structure and the new array without worrying about
what the values now look like.

Signed-off-by: John Keeping <john@keeping.me.uk>

1 files changed, 20 insertions, 37 deletions

diff --git a/cache.c b/cache.c
index 3127fc2..c1d777b 100644
--- a/cache.c
+++ b/cache.c
@@ -312,9 +312,9 @@ int cache_process(int size, const char *path, const char *key, int ttl,
 		  cache_fill_fn fn, void *cbdata)
 {
 	unsigned long hash;
-	int len, i;
-	char filename[1024];
-	char lockname[1024 + 5];  /* 5 = ".lock" */
+	int i;
+	struct strbuf filename = STRBUF_INIT;
+	struct strbuf lockname = STRBUF_INIT;
 	struct cache_slot slot;
 
 	/* If the cache is disabled, just generate the content */
@@ -329,32 +329,22 @@ int cache_process(int size, const char *path, const char *key, int ttl,
 		fn(cbdata);
 		return 0;
 	}
-	len = strlen(path);
-	if (len > sizeof(filename) - 10) { /* 10 = "/01234567\0" */
-		cache_log("[cgit] Cache path too long, caching is disabled: %s\n",
-			  path);
-		fn(cbdata);
-		return 0;
-	}
 	if (!key)
 		key = "";
 	hash = hash_str(key) % size;
-	strcpy(filename, path);
-	if (filename[len - 1] != '/')
-		filename[len++] = '/';
+	strbuf_addstr(&filename, path);
+	strbuf_ensure_end(&filename, '/');
 	for (i = 0; i < 8; i++) {
-		sprintf(filename + len++, "%x",
-			(unsigned char)(hash & 0xf));
+		strbuf_addf(&filename, "%x", (unsigned char)(hash & 0xf));
 		hash >>= 4;
 	}
-	filename[len] = '\0';
-	strcpy(lockname, filename);
-	strcpy(lockname + len, ".lock");
+	strbuf_addbuf(&lockname, &filename);
+	strbuf_addstr(&lockname, ".lock");
 	slot.fn = fn;
 	slot.cbdata = cbdata;
 	slot.ttl = ttl;
-	slot.cache_name = filename;
-	slot.lock_name = lockname;
+	slot.cache_name = strbuf_detach(&filename, NULL);
+	slot.lock_name = strbuf_detach(&lockname, NULL);
 	slot.key = key;
 	slot.keylen = strlen(key);
 	return process_slot(&slot);
@@ -381,18 +371,13 @@ int cache_ls(const char *path)
 	struct dirent *ent;
 	int err = 0;
 	struct cache_slot slot;
-	char fullname[1024];
-	char *name;
+	struct strbuf fullname = STRBUF_INIT;
+	size_t prefixlen;
 
 	if (!path) {
 		cache_log("[cgit] cache path not specified\n");
 		return -1;
 	}
-	if (strlen(path) > 1024 - 10) {
-		cache_log("[cgit] cache path too long: %s\n",
-			  path);
-		return -1;
-	}
 	dir = opendir(path);
 	if (!dir) {
 		err = errno;
@@ -400,30 +385,28 @@ int cache_ls(const char *path)
 			  path, strerror(err), err);
 		return err;
 	}
-	strcpy(fullname, path);
-	name = fullname + strlen(path);
-	if (*(name - 1) != '/') {
-		*name++ = '/';
-		*name = '\0';
-	}
-	slot.cache_name = fullname;
+	strbuf_addstr(&fullname, path);
+	strbuf_ensure_end(&fullname, '/');
+	prefixlen = fullname.len;
 	while ((ent = readdir(dir)) != NULL) {
 		if (strlen(ent->d_name) != 8)
 			continue;
-		strcpy(name, ent->d_name);
+		strbuf_setlen(&fullname, prefixlen);
+		strbuf_addstr(&fullname, ent->d_name);
 		if ((err = open_slot(&slot)) != 0) {
 			cache_log("[cgit] unable to open path %s: %s (%d)\n",
-				  fullname, strerror(err), err);
+				  fullname.buf, strerror(err), err);
 			continue;
 		}
 		printf("%s %s %10"PRIuMAX" %s\n",
-		       name,
+		       fullname.buf,
 		       sprintftime("%Y-%m-%d %H:%M:%S",
 				   slot.cache_st.st_mtime),
 		       (uintmax_t)slot.cache_st.st_size,
 		       slot.buf);
 		close_slot(&slot);
 	}
+	slot.cache_name = strbuf_detach(&fullname, NULL);
 	closedir(dir);
 	return 0;
 }