optimization: only diff the tree when it is needed for the diffstat...

... also clear all fields in the structure on failure.

This is not as big an optimization as stagit-gopher, because the diffstat is
displayed in the log, but the difference is still measurable.

diff --git a/stagit.c b/stagit.c
index 81fdd1d15faef622e0b25d94225136c3b4de33dd..6c9b5c0def1b3ac717abe3629782dd1a0cad1504 100644 (file)
--- a/stagit.c
+++ b/stagit.c
@@ -87,7 +87,7 @@ deltainfo_free(struct deltainfo *di)
        if (!di)
                return;
        git_patch_free(di->patch);
-       di->patch = NULL;
+       memset(di, 0, sizeof(*di));
        free(di);
 }
 
@@ -95,6 +95,7 @@ int
 commitinfo_getstats(struct commitinfo *ci)
 {
        struct deltainfo *di;
+       git_diff_options opts;
        const git_diff_delta *delta;
        const git_diff_hunk *hunk;
        const git_diff_line *line;
@@ -102,6 +103,20 @@ commitinfo_getstats(struct commitinfo *ci)
        size_t ndeltas, nhunks, nhunklines;
        size_t i, j, k;
 
+       if (git_tree_lookup(&(ci->commit_tree), repo, git_commit_tree_id(ci->commit)))
+               goto err;
+       if (!git_commit_parent(&(ci->parent), ci->commit, 0)) {
+               if (git_tree_lookup(&(ci->parent_tree), repo, git_commit_tree_id(ci->parent))) {
+                       ci->parent = NULL;
+                       ci->parent_tree = NULL;
+               }
+       }
+
+       git_diff_init_options(&opts, GIT_DIFF_OPTIONS_VERSION);
+       opts.flags |= GIT_DIFF_DISABLE_PATHSPEC_MATCH;
+       if (git_diff_tree_to_tree(&(ci->diff), repo, ci->parent_tree, ci->commit_tree, &opts))
+               goto err;
+
        ndeltas = git_diff_num_deltas(ci->diff);
        if (ndeltas && !(ci->deltas = calloc(ndeltas, sizeof(struct deltainfo *))))
                err(1, "calloc");
@@ -143,6 +158,15 @@ commitinfo_getstats(struct commitinfo *ci)
        return 0;
 
 err:
+       git_diff_free(ci->diff);
+       ci->diff = NULL;
+       git_tree_free(ci->commit_tree);
+       ci->commit_tree = NULL;
+       git_tree_free(ci->parent_tree);
+       ci->parent_tree = NULL;
+       git_commit_free(ci->parent);
+       ci->parent = NULL;
+
        if (ci->deltas)
                for (i = 0; i < ci->ndeltas; i++)
                        deltainfo_free(ci->deltas[i]);
@@ -166,13 +190,14 @@ commitinfo_free(struct commitinfo *ci)
        if (ci->deltas)
                for (i = 0; i < ci->ndeltas; i++)
                        deltainfo_free(ci->deltas[i]);
+
        free(ci->deltas);
-       ci->deltas = NULL;
        git_diff_free(ci->diff);
        git_tree_free(ci->commit_tree);
        git_tree_free(ci->parent_tree);
        git_commit_free(ci->commit);
        git_commit_free(ci->parent);
+       memset(ci, 0, sizeof(*ci));
        free(ci);
 }
 
@@ -180,7 +205,6 @@ struct commitinfo *
 commitinfo_getbyoid(const git_oid *id)
 {
        struct commitinfo *ci;
-       git_diff_options opts;
 
        if (!(ci = calloc(1, sizeof(struct commitinfo))))
                err(1, "calloc");
@@ -197,20 +221,6 @@ commitinfo_getbyoid(const git_oid *id)
        ci->summary = git_commit_summary(ci->commit);
        ci->msg = git_commit_message(ci->commit);
 
-       if (git_tree_lookup(&(ci->commit_tree), repo, git_commit_tree_id(ci->commit)))
-               goto err;
-       if (!git_commit_parent(&(ci->parent), ci->commit, 0)) {
-               if (git_tree_lookup(&(ci->parent_tree), repo, git_commit_tree_id(ci->parent))) {
-                       ci->parent = NULL;
-                       ci->parent_tree = NULL;
-               }
-       }
-
-       git_diff_init_options(&opts, GIT_DIFF_OPTIONS_VERSION);
-       opts.flags |= GIT_DIFF_DISABLE_PATHSPEC_MATCH;
-       if (git_diff_tree_to_tree(&(ci->diff), repo, ci->parent_tree, ci->commit_tree, &opts))
-               goto err;
-
        return ci;
 
 err: