Merge branch 'rs/sha1-name-readdir-optim'

Optimize "what are the object names already taken in an alternate
object database?" query that is used to derive the length of prefix
an object name is uniquely abbreviated to.

* rs/sha1-name-readdir-optim:
  sha1_file: guard against invalid loose subdirectory numbers
  sha1_file: let for_each_file_in_obj_subdir() handle subdir names
  p4205: add perf test script for pretty log formats
  sha1_name: cache readdir(3) results in find_short_object_filename()

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 87c6756..99dea7a 100644 (file)
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -537,7 +537,7 @@ static int fsck_cruft(const char *basename, const char *path, void *data)
        return 0;
 }
 
-static int fsck_subdir(int nr, const char *path, void *progress)
+static int fsck_subdir(unsigned int nr, const char *path, void *progress)
 {
        display_progress(progress, nr + 1);
        return 0;

diff --git a/builtin/prune-packed.c b/builtin/prune-packed.c
index c026299..ac978ad 100644 (file)
--- a/builtin/prune-packed.c
+++ b/builtin/prune-packed.c
@@ -10,7 +10,7 @@ static const char * const prune_packed_usage[] = {
 
 static struct progress *progress;
 
-static int prune_subdir(int nr, const char *path, void *data)
+static int prune_subdir(unsigned int nr, const char *path, void *data)
 {
        int *opts = data;
        display_progress(progress, nr + 1);

diff --git a/builtin/prune.c b/builtin/prune.c
index f0e2bff..c378690 100644 (file)
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@ -68,7 +68,7 @@ static int prune_cruft(const char *basename, const char *path, void *data)
        return 0;
 }
 
-static int prune_subdir(int nr, const char *path, void *data)
+static int prune_subdir(unsigned int nr, const char *path, void *data)
 {
        if (!show_only)
                rmdir(path);

diff --git a/cache.h b/cache.h
index c958fc3..c12f452 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -12,6 +12,7 @@
 #include "pack-revindex.h"
 #include "hash.h"
 #include "path.h"
+#include "sha1-array.h"
 
 #ifndef platform_SHA_CTX
 /*
@@ -1540,6 +1541,16 @@ extern struct alternate_object_database {
        struct strbuf scratch;
        size_t base_len;
 
+       /*
+        * Used to store the results of readdir(3) calls when searching
+        * for unique abbreviated hashes.  This cache is never
+        * invalidated, thus it's racy and not necessarily accurate.
+        * That's fine for its purpose; don't use it for tasks requiring
+        * greater accuracy!
+        */
+       char loose_objects_subdir_seen[256];
+       struct oid_array loose_objects_cache;
+
        char path[FLEX_ARRAY];
 } *alt_odb_list;
 extern void prepare_alt_odb(void);
@@ -1755,9 +1766,15 @@ typedef int each_loose_object_fn(const struct object_id *oid,
 typedef int each_loose_cruft_fn(const char *basename,
                                const char *path,
                                void *data);
-typedef int each_loose_subdir_fn(int nr,
+typedef int each_loose_subdir_fn(unsigned int nr,
                                 const char *path,
                                 void *data);
+int for_each_file_in_obj_subdir(unsigned int subdir_nr,
+                               struct strbuf *path,
+                               each_loose_object_fn obj_cb,
+                               each_loose_cruft_fn cruft_cb,
+                               each_loose_subdir_fn subdir_cb,
+                               void *data);
 int for_each_loose_file_in_objdir(const char *path,
                                  each_loose_object_fn obj_cb,
                                  each_loose_cruft_fn cruft_cb,

diff --git a/sha1_file.c b/sha1_file.c
index fb1fd80..9a9f7f7 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -3735,22 +3735,32 @@ void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
                    typename(expect));
 }
 
-static int for_each_file_in_obj_subdir(int subdir_nr,
-                                      struct strbuf *path,
-                                      each_loose_object_fn obj_cb,
-                                      each_loose_cruft_fn cruft_cb,
-                                      each_loose_subdir_fn subdir_cb,
-                                      void *data)
-{
-       size_t baselen = path->len;
-       DIR *dir = opendir(path->buf);
+int for_each_file_in_obj_subdir(unsigned int subdir_nr,
+                               struct strbuf *path,
+                               each_loose_object_fn obj_cb,
+                               each_loose_cruft_fn cruft_cb,
+                               each_loose_subdir_fn subdir_cb,
+                               void *data)
+{
+       size_t origlen, baselen;
+       DIR *dir;
        struct dirent *de;
        int r = 0;
 
+       if (subdir_nr > 0xff)
+               BUG("invalid loose object subdirectory: %x", subdir_nr);
+
+       origlen = path->len;
+       strbuf_complete(path, '/');
+       strbuf_addf(path, "%02x", subdir_nr);
+       baselen = path->len;
+
+       dir = opendir(path->buf);
        if (!dir) {
-               if (errno == ENOENT)
-                       return 0;
-               return error_errno("unable to open %s", path->buf);
+               if (errno != ENOENT)
+                       r = error_errno("unable to open %s", path->buf);
+               strbuf_setlen(path, origlen);
+               return r;
        }
 
        while ((de = readdir(dir))) {
@@ -3788,6 +3798,8 @@ static int for_each_file_in_obj_subdir(int subdir_nr,
        if (!r && subdir_cb)
                r = subdir_cb(subdir_nr, path->buf, data);
 
+       strbuf_setlen(path, origlen);
+
        return r;
 }
 
@@ -3797,15 +3809,12 @@ int for_each_loose_file_in_objdir_buf(struct strbuf *path,
                            each_loose_subdir_fn subdir_cb,
                            void *data)
 {
-       size_t baselen = path->len;
        int r = 0;
        int i;
 
        for (i = 0; i < 256; i++) {
-               strbuf_addf(path, "/%02x", i);
                r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
                                                subdir_cb, data);
-               strbuf_setlen(path, baselen);
                if (r)
                        break;
        }

diff --git a/sha1_name.c b/sha1_name.c
index d2d732c..e7f7b12 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -78,10 +78,19 @@ static void update_candidates(struct disambiguate_state *ds, const struct object
        /* otherwise, current can be discarded and candidate is still good */
 }
 
+static int append_loose_object(const struct object_id *oid, const char *path,
+                              void *data)
+{
+       oid_array_append(data, oid);
+       return 0;
+}
+
+static int match_sha(unsigned, const unsigned char *, const unsigned char *);
+
 static void find_short_object_filename(struct disambiguate_state *ds)
 {
+       int subdir_nr = ds->bin_pfx.hash[0];
        struct alternate_object_database *alt;
-       char hex[GIT_MAX_HEXSZ];
        static struct alternate_object_database *fakeent;
 
        if (!fakeent) {
@@ -96,29 +105,29 @@ static void find_short_object_filename(struct disambiguate_state *ds)
        }
        fakeent->next = alt_odb_list;
 
-       xsnprintf(hex, sizeof(hex), "%.2s", ds->hex_pfx);
        for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
-               struct strbuf *buf = alt_scratch_buf(alt);
-               struct dirent *de;
-               DIR *dir;
-
-               strbuf_addf(buf, "%.2s/", ds->hex_pfx);
-               dir = opendir(buf->buf);
-               if (!dir)
-                       continue;
+               int pos;
 
-               while (!ds->ambiguous && (de = readdir(dir)) != NULL) {
-                       struct object_id oid;
+               if (!alt->loose_objects_subdir_seen[subdir_nr]) {
+                       struct strbuf *buf = alt_scratch_buf(alt);
+                       for_each_file_in_obj_subdir(subdir_nr, buf,
+                                                   append_loose_object,
+                                                   NULL, NULL,
+                                                   &alt->loose_objects_cache);
+                       alt->loose_objects_subdir_seen[subdir_nr] = 1;
+               }
 
-                       if (strlen(de->d_name) != GIT_SHA1_HEXSZ - 2)
-                               continue;
-                       if (memcmp(de->d_name, ds->hex_pfx + 2, ds->len - 2))
-                               continue;
-                       memcpy(hex + 2, de->d_name, GIT_SHA1_HEXSZ - 2);
-                       if (!get_oid_hex(hex, &oid))
-                               update_candidates(ds, &oid);
+               pos = oid_array_lookup(&alt->loose_objects_cache, &ds->bin_pfx);
+               if (pos < 0)
+                       pos = -1 - pos;
+               while (!ds->ambiguous && pos < alt->loose_objects_cache.nr) {
+                       const struct object_id *oid;
+                       oid = alt->loose_objects_cache.oid + pos;
+                       if (!match_sha(ds->len, ds->bin_pfx.hash, oid->hash))
+                               break;
+                       update_candidates(ds, oid);
+                       pos++;
                }
-               closedir(dir);
        }
 }
 

diff --git a/t/perf/p4205-log-pretty-formats.sh b/t/perf/p4205-log-pretty-formats.sh
new file mode 100755 (executable)
index 0000000..7c26f4f
--- /dev/null
+++ b/t/perf/p4205-log-pretty-formats.sh
@@ -0,0 +1,16 @@
+#!/bin/sh
+
+test_description='Tests the performance of various pretty format placeholders'
+
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+for format in %H %h %T %t %P %p %h-%h-%h
+do
+       test_perf "log with $format" "
+               git log --format=\"$format\" >/dev/null
+       "
+done
+
+test_done