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, 36 insertions, 36 deletions

diff --git a/cgit.c b/cgit.c
index 4e51283..f73c7b0 100644
--- a/cgit.c
+++ b/cgit.c
@@ -468,8 +468,8 @@ static int prepare_repo_cmd(struct cgit_context *ctx)
         if (nongit) {
                 const char *name = ctx->repo->name;
                 rc = errno;
-                ctx->page.title = fmt("%s - %s", ctx->cfg.root_title,
-                                      "config error");
+                ctx->page.title = fmtalloc("%s - %s", ctx->cfg.root_title,
+                                                "config error");
                 ctx->repo = NULL;
                 cgit_print_http_headers(ctx);
                 cgit_print_docstart(ctx);
@@ -479,7 +479,7 @@ static int prepare_repo_cmd(struct cgit_context *ctx)
                 cgit_print_docend();
                 return 1;
         }
-        ctx->page.title = fmt("%s - %s", ctx->repo->name, ctx->repo->desc);
+        ctx->page.title = fmtalloc("%s - %s", ctx->repo->name, ctx->repo->desc);
 
         if (!ctx->repo->defbranch)
                 ctx->repo->defbranch = guess_defbranch();
@@ -577,21 +577,16 @@ static int cmp_repos(const void *a, const void *b)
 static char *build_snapshot_setting(int bitmap)
 {
         const struct cgit_snapshot_format *f;
-        char *result = xstrdup("");
-        char *tmp;
-        int len;
+        struct strbuf result = STRBUF_INIT;
 
         for (f = cgit_snapshot_formats; f->suffix; f++) {
                 if (f->bit & bitmap) {
-                        tmp = result;
-                        result = xstrdup(fmt("%s%s ", tmp, f->suffix));
-                        free(tmp);
+                        if (result.len)
+                                strbuf_addch(&result, ' ');
+                        strbuf_addstr(&result, f->suffix);
                 }
         }
-        len = strlen(result);
-        if (len)
-                result[len - 1] = '\0';
-        return result;
+        return strbuf_detach(&result, NULL);
 }
 
 static char *get_first_line(char *txt)
@@ -639,7 +634,7 @@ static void print_repo(FILE *f, struct cgit_repo *repo)
                 fprintf(f, "repo.source-filter=%s\n", repo->source_filter->cmd);
         if (repo->snapshots != ctx.cfg.snapshots) {
                 char *tmp = build_snapshot_setting(repo->snapshots);
-                fprintf(f, "repo.snapshots=%s\n", tmp);
+                fprintf(f, "repo.snapshots=%s\n", tmp ? tmp : "");
                 free(tmp);
         }
         if (repo->max_stats != ctx.cfg.max_stats)
@@ -661,20 +656,22 @@ static void print_repolist(FILE *f, struct cgit_repolist *list, int start)
  */
 static int generate_cached_repolist(const char *path, const char *cached_rc)
 {
-        char *locked_rc;
+        struct strbuf locked_rc = STRBUF_INIT;
+        int result = 0;
         int idx;
         FILE *f;
 
-        locked_rc = xstrdup(fmt("%s.lock", cached_rc));
-        f = fopen(locked_rc, "wx");
+        strbuf_addf(&locked_rc, "%s.lock", cached_rc);
+        f = fopen(locked_rc.buf, "wx");
         if (!f) {
                 /* Inform about the error unless the lockfile already existed,
                  * since that only means we've got concurrent requests.
                  */
-                if (errno != EEXIST)
+                result = errno;
+                if (result != EEXIST)
                         fprintf(stderr, "[cgit] Error opening %s: %s (%d)\n",
-                                locked_rc, strerror(errno), errno);
-                return errno;
+                                locked_rc.buf, strerror(result), result);
+                goto out;
         }
         idx = cgit_repolist.count;
         if (ctx.cfg.project_list)
@@ -682,55 +679,59 @@ static int generate_cached_repolist(const char *path, const char *cached_rc)
         else
                 scan_tree(path, repo_config);
         print_repolist(f, &cgit_repolist, idx);
-        if (rename(locked_rc, cached_rc))
+        if (rename(locked_rc.buf, cached_rc))
                 fprintf(stderr, "[cgit] Error renaming %s to %s: %s (%d)\n",
-                        locked_rc, cached_rc, strerror(errno), errno);
+                        locked_rc.buf, cached_rc, strerror(errno), errno);
         fclose(f);
-        return 0;
+out:
+        strbuf_release(&locked_rc);
+        return result;
 }
 
 static void process_cached_repolist(const char *path)
 {
         struct stat st;
-        char *cached_rc;
+        struct strbuf cached_rc = STRBUF_INIT;
         time_t age;
         unsigned long hash;
 
         hash = hash_str(path);
         if (ctx.cfg.project_list)
                 hash += hash_str(ctx.cfg.project_list);
-        cached_rc = xstrdup(fmt("%s/rc-%8lx", ctx.cfg.cache_root, hash));
+        strbuf_addf(&cached_rc, "%s/rc-%8lx", ctx.cfg.cache_root, hash);
 
-        if (stat(cached_rc, &st)) {
+        if (stat(cached_rc.buf, &st)) {
                 /* Nothing is cached, we need to scan without forking. And
                  * if we fail to generate a cached repolist, we need to
                  * invoke scan_tree manually.
                  */
-                if (generate_cached_repolist(path, cached_rc)) {
+                if (generate_cached_repolist(path, cached_rc.buf)) {
                         if (ctx.cfg.project_list)
                                 scan_projects(path, ctx.cfg.project_list,
                                               repo_config);
                         else
                                 scan_tree(path, repo_config);
                 }
-                return;
+                goto out;
         }
 
-        parse_configfile(cached_rc, config_cb);
+        parse_configfile(cached_rc.buf, config_cb);
 
         /* If the cached configfile hasn't expired, lets exit now */
         age = time(NULL) - st.st_mtime;
         if (age <= (ctx.cfg.cache_scanrc_ttl * 60))
-                return;
+                goto out;
 
         /* The cached repolist has been parsed, but it was old. So lets
          * rescan the specified path and generate a new cached repolist
          * in a child-process to avoid latency for the current request.
          */
         if (fork())
-                return;
+                goto out;
 
-        exit(generate_cached_repolist(path, cached_rc));
+        exit(generate_cached_repolist(path, cached_rc.buf));
+out:
+        strbuf_release(&cached_rc);
 }
 
 static void cgit_parse_args(int argc, const char **argv)
@@ -812,7 +813,6 @@ static int calc_ttl()
 int main(int argc, const char **argv)
 {
         const char *path;
-        char *qry;
         int err, ttl;
 
         prepare_context(&ctx);
@@ -843,9 +843,9 @@ int main(int argc, const char **argv)
                         path++;
                 ctx.qry.url = xstrdup(path);
                 if (ctx.qry.raw) {
-                        qry = ctx.qry.raw;
-                        ctx.qry.raw = xstrdup(fmt("%s?%s", path, qry));
-                        free(qry);
+                        char *newqry = fmtalloc("%s?%s", path, ctx.qry.raw);
+                        free(ctx.qry.raw);
+                        ctx.qry.raw = newqry;
                 } else
                         ctx.qry.raw = xstrdup(ctx.qry.url);
                 cgit_parse_url(ctx.qry.url);