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From: Jeff King <peff@peff.net>
To: Derrick Stolee <stolee@gmail.com>
Cc: "SZEDER Gábor" <szeder.dev@gmail.com>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Stefan Beller" <sbeller@google.com>, git <git@vger.kernel.org>,
	"Duy Nguyen" <pclouds@gmail.com>
Subject: [PoC -- do not apply 1/3] initial tree-bitmap proof of concept
Date: Tue, 9 Oct 2018 19:13:32 -0400
Message-ID: <20181009231331.GA23730@sigill.intra.peff.net> (raw)
In-Reply-To: <20181009231250.GA19342@sigill.intra.peff.net>

Signed-off-by: Jeff King <peff@peff.net>
---
 Makefile                    |   1 +
 t/helper/test-tree-bitmap.c | 167 ++++++++++++++++++++++++++++++++++++
 2 files changed, 168 insertions(+)
 create mode 100644 t/helper/test-tree-bitmap.c

diff --git a/Makefile b/Makefile
index 13e1c52478..f6e823f2d6 100644
--- a/Makefile
+++ b/Makefile
@@ -751,6 +751,7 @@ TEST_PROGRAMS_NEED_X += test-parse-options
 TEST_PROGRAMS_NEED_X += test-pkt-line
 TEST_PROGRAMS_NEED_X += test-svn-fe
 TEST_PROGRAMS_NEED_X += test-tool
+TEST_PROGRAMS_NEED_X += test-tree-bitmap
 
 TEST_PROGRAMS = $(patsubst %,t/helper/%$X,$(TEST_PROGRAMS_NEED_X))
 
diff --git a/t/helper/test-tree-bitmap.c b/t/helper/test-tree-bitmap.c
new file mode 100644
index 0000000000..bc5cf0e514
--- /dev/null
+++ b/t/helper/test-tree-bitmap.c
@@ -0,0 +1,167 @@
+#include "cache.h"
+#include "revision.h"
+#include "diffcore.h"
+#include "argv-array.h"
+#include "ewah/ewok.h"
+
+/* map of pathnames to bit positions */
+struct pathmap_entry {
+	struct hashmap_entry ent;
+	unsigned pos;
+	char path[FLEX_ARRAY];
+};
+
+static int pathmap_entry_hashcmp(const void *unused_cmp_data,
+				 const void *entry,
+				 const void *entry_or_key,
+				 const void *keydata)
+{
+	const struct pathmap_entry *a = entry;
+	const struct pathmap_entry *b = entry_or_key;
+	const char *key = keydata;
+
+	return strcmp(a->path, key ? key : b->path);
+}
+
+static int pathmap_entry_strcmp(const void *va, const void *vb)
+{
+	struct pathmap_entry *a = *(struct pathmap_entry **)va;
+	struct pathmap_entry *b = *(struct pathmap_entry **)vb;
+	return strcmp(a->path, b->path);
+}
+
+struct walk_paths_data {
+	struct hashmap *paths;
+	struct commit *commit;
+};
+
+static void walk_paths(diff_format_fn_t fn, struct hashmap *paths)
+{
+	struct argv_array argv = ARGV_ARRAY_INIT;
+	struct rev_info revs;
+	struct walk_paths_data data;
+	struct commit *commit;
+
+	argv_array_pushl(&argv, "rev-list",
+			 "--all", "-t", "--no-renames",
+			 NULL);
+	init_revisions(&revs, NULL);
+	setup_revisions(argv.argc, argv.argv, &revs, NULL);
+	revs.diffopt.output_format = DIFF_FORMAT_CALLBACK;
+	revs.diffopt.format_callback = fn;
+	revs.diffopt.format_callback_data = &data;
+
+	data.paths = paths;
+
+	prepare_revision_walk(&revs);
+	while ((commit = get_revision(&revs))) {
+		data.commit = commit;
+		diff_tree_combined_merge(commit, 0, &revs);
+	}
+
+	reset_revision_walk();
+	argv_array_clear(&argv);
+}
+
+static void collect_commit_paths(struct diff_queue_struct *q,
+				 struct diff_options *opts,
+				 void *vdata)
+{
+	struct walk_paths_data *data = vdata;
+	int i;
+
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filepair *p = q->queue[i];
+		const char *path = p->one->path;
+		struct pathmap_entry *entry;
+		struct hashmap_entry lookup;
+
+		hashmap_entry_init(&lookup, strhash(path));
+		entry = hashmap_get(data->paths, &lookup, path);
+		if (entry)
+			continue; /* already present */
+
+		FLEX_ALLOC_STR(entry, path, path);
+		entry->ent = lookup;
+		hashmap_put(data->paths, entry);
+	}
+}
+
+/* assign a bit position to all possible paths */
+static void collect_paths(struct hashmap *paths)
+{
+	struct pathmap_entry **sorted;
+	size_t i, n;
+	struct hashmap_iter iter;
+	struct pathmap_entry *entry;
+
+	/* grab all unique paths */
+	hashmap_init(paths, pathmap_entry_hashcmp, NULL, 0);
+	walk_paths(collect_commit_paths, paths);
+
+	/* and assign them bits in sorted order */
+	n = hashmap_get_size(paths);
+	ALLOC_ARRAY(sorted, n);
+	i = 0;
+	for (entry = hashmap_iter_first(paths, &iter);
+	     entry;
+	     entry = hashmap_iter_next(&iter)) {
+		assert(i < n);
+		sorted[i++] = entry;
+	}
+	QSORT(sorted, i, pathmap_entry_strcmp);
+	for (i = 0; i < n; i++)
+		sorted[i]->pos = i;
+	free(sorted);
+}
+
+/* generate the bitmap for a single commit */
+static void generate_bitmap(struct diff_queue_struct *q,
+			    struct diff_options *opts,
+			    void *vdata)
+{
+	struct walk_paths_data *data = vdata;
+	struct bitmap *bitmap = bitmap_new();
+	struct ewah_bitmap *ewah;
+	struct strbuf out = STRBUF_INIT;
+	size_t i;
+
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filepair *p = q->queue[i];
+		const char *path = p->one->path;
+		struct pathmap_entry *entry;
+		struct hashmap_entry lookup;
+
+		hashmap_entry_init(&lookup, strhash(path));
+		entry = hashmap_get(data->paths, &lookup, path);
+		if (!entry)
+			BUG("mysterious path appeared: %s", path);
+
+		bitmap_set(bitmap, entry->pos);
+	}
+
+	ewah = bitmap_to_ewah(bitmap);
+	ewah_serialize_strbuf(ewah, &out);
+	fwrite(out.buf, 1, out.len, stdout);
+
+	trace_printf("bitmap %s %u %u",
+		     oid_to_hex(&data->commit->object.oid),
+		     (unsigned)q->nr,
+		     (unsigned)out.len);
+
+	strbuf_release(&out);
+	ewah_free(ewah);
+	bitmap_free(bitmap);
+}
+
+int cmd_main(int argc, const char **argv)
+{
+	struct hashmap paths;
+
+	setup_git_directory();
+	collect_paths(&paths);
+
+	walk_paths(generate_bitmap, &paths);
+
+	return 0;
+}
-- 
2.19.1.550.g7610f1eecb


  reply index

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-03 13:23 We should add a "git gc --auto" after "git clone" due to commit graph Ævar Arnfjörð Bjarmason
2018-10-03 13:36 ` SZEDER Gábor
2018-10-03 13:42   ` Derrick Stolee
2018-10-03 14:18     ` Ævar Arnfjörð Bjarmason
2018-10-03 14:01   ` Ævar Arnfjörð Bjarmason
2018-10-03 14:17     ` SZEDER Gábor
2018-10-03 14:22       ` Ævar Arnfjörð Bjarmason
2018-10-03 14:53         ` SZEDER Gábor
2018-10-03 15:19           ` Ævar Arnfjörð Bjarmason
2018-10-03 16:59             ` SZEDER Gábor
2018-10-05  6:09               ` Junio C Hamano
2018-10-10 22:07                 ` SZEDER Gábor
2018-10-10 23:01                   ` Ævar Arnfjörð Bjarmason
2018-10-03 19:08           ` Stefan Beller
2018-10-03 19:21             ` Jeff King
2018-10-03 20:35               ` Ævar Arnfjörð Bjarmason
2018-10-03 17:47         ` Stefan Beller
2018-10-03 18:47           ` Ævar Arnfjörð Bjarmason
2018-10-03 18:51             ` Jeff King
2018-10-03 18:59               ` Derrick Stolee
2018-10-03 19:18                 ` Jeff King
2018-10-08 16:41                   ` SZEDER Gábor
2018-10-08 16:57                     ` Derrick Stolee
2018-10-08 18:10                       ` SZEDER Gábor
2018-10-08 18:29                         ` Derrick Stolee
2018-10-09  3:08                           ` Jeff King
2018-10-09 13:48                             ` Bloom Filters (was Re: We should add a "git gc --auto" after "git clone" due to commit graph) Derrick Stolee
2018-10-09 18:45                               ` Ævar Arnfjörð Bjarmason
2018-10-09 18:46                               ` Jeff King
2018-10-09 19:03                                 ` Derrick Stolee
2018-10-09 21:14                                   ` Jeff King
2018-10-09 23:12                                     ` Bloom Filters Jeff King
2018-10-09 23:13                                       ` Jeff King [this message]
2018-10-09 23:14                                       ` [PoC -- do not apply 2/3] test-tree-bitmap: add "dump" mode Jeff King
2018-10-10  0:48                                         ` Junio C Hamano
2018-10-11  3:13                                           ` Jeff King
2018-10-09 23:14                                       ` [PoC -- do not apply 3/3] test-tree-bitmap: replace ewah with custom rle encoding Jeff King
2018-10-10  0:58                                         ` Junio C Hamano
2018-10-11  3:20                                           ` Jeff King
2018-10-11 12:33                                       ` Bloom Filters Derrick Stolee
2018-10-11 13:43                                         ` Jeff King
2018-10-09 21:30                             ` We should add a "git gc --auto" after "git clone" due to commit graph SZEDER Gábor
2018-10-09 19:34                       ` [PATCH 0/4] Bloom filter experiment SZEDER Gábor
2018-10-09 19:34                         ` [PATCH 1/4] Add a (very) barebones Bloom filter implementation SZEDER Gábor
2018-10-09 19:34                         ` [PATCH 2/4] commit-graph: write a Bloom filter containing changed paths for each commit SZEDER Gábor
2018-10-09 21:06                           ` Jeff King
2018-10-09 21:37                             ` SZEDER Gábor
2018-10-09 19:34                         ` [PATCH 3/4] revision.c: use the Bloom filter to speed up path-limited revision walks SZEDER Gábor
2018-10-09 19:34                         ` [PATCH 4/4] revision.c: add GIT_TRACE_BLOOM_FILTER for a bit of statistics SZEDER Gábor
2018-10-09 19:47                         ` [PATCH 0/4] Bloom filter experiment Derrick Stolee
2018-10-11  1:21                         ` [PATCH 0/2] Per-commit filter proof of concept Jonathan Tan
2018-10-11  1:21                           ` [PATCH 1/2] One filter per commit Jonathan Tan
2018-10-11  1:21                           ` [PATCH 2/2] Only make bloom filter for first parent Jonathan Tan
2018-10-11  7:37                           ` [PATCH 0/2] Per-commit filter proof of concept Ævar Arnfjörð Bjarmason
2018-10-15 14:39                         ` [PATCH 0/4] Bloom filter experiment Derrick Stolee
2018-10-16  4:45                           ` Junio C Hamano
2018-10-16 11:13                             ` Derrick Stolee
2018-10-16 12:57                               ` Ævar Arnfjörð Bjarmason
2018-10-16 13:03                                 ` Derrick Stolee
2018-10-18  2:00                                 ` Junio C Hamano
2018-10-16 23:41                           ` Jonathan Tan
2018-10-08 23:02                     ` We should add a "git gc --auto" after "git clone" due to commit graph Junio C Hamano
2018-10-03 14:32     ` Duy Nguyen
2018-10-03 16:45 ` Duy Nguyen
2018-10-04 21:42 ` [RFC PATCH] " Ævar Arnfjörð Bjarmason
2018-10-05 12:05   ` Derrick Stolee
2018-10-05 13:05     ` Ævar Arnfjörð Bjarmason
2018-10-05 13:45       ` Derrick Stolee
2018-10-05 14:04         ` Ævar Arnfjörð Bjarmason
2018-10-05 19:21         ` Jeff King
2018-10-05 19:41           ` Derrick Stolee
2018-10-05 19:47             ` Jeff King
2018-10-05 20:00               ` Derrick Stolee
2018-10-05 20:02                 ` Jeff King
2018-10-05 20:01               ` Ævar Arnfjörð Bjarmason
2018-10-05 20:09                 ` Jeff King
2018-10-11 12:49 [PATCH 1/2] One filter per commit Derrick Stolee
2018-10-11 19:11 ` [PATCH] Per-commit and per-parent filters for 2 parents Jonathan Tan

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