From: Michael Haggerty <mhagger@alum.mit.edu>
To: Junio C Hamano <gitster@pobox.com>
Cc: "Stefan Beller" <sbeller@google.com>,
"Johannes Schindelin" <Johannes.Schindelin@gmx.de>,
"Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>,
"Jeff King" <peff@peff.net>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
"Brandon Williams" <bmwill@google.com>,
git@vger.kernel.org, "Michael Haggerty" <mhagger@alum.mit.edu>
Subject: [PATCH v2 20/21] mmapped_ref_iterator: inline into `packed_ref_iterator`
Date: Tue, 19 Sep 2017 08:22:28 +0200 [thread overview]
Message-ID: <7e2152dc4d05bee9e822c4a9690a2c9d3b2fce6b.1505799700.git.mhagger@alum.mit.edu> (raw)
In-Reply-To: <cover.1505799700.git.mhagger@alum.mit.edu>
Since `packed_ref_iterator` is now delegating to
`mmapped_ref_iterator` rather than `cache_ref_iterator` to do the
heavy lifting, there is no need to keep the two iterators separate. So
"inline" `mmapped_ref_iterator` into `packed_ref_iterator`. This
removes a bunch of boilerplate.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
refs/packed-backend.c | 284 ++++++++++++++++++++------------------------------
1 file changed, 114 insertions(+), 170 deletions(-)
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index b1571872fa..92b837a237 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -225,157 +225,6 @@ static NORETURN void die_invalid_line(const char *path,
}
-/*
- * This value is set in `base.flags` if the peeled value of the
- * current reference is known. In that case, `peeled` contains the
- * correct peeled value for the reference, which might be `null_sha1`
- * if the reference is not a tag or if it is broken.
- */
-#define REF_KNOWS_PEELED 0x40
-
-/*
- * An iterator over a packed-refs file that is currently mmapped.
- */
-struct mmapped_ref_iterator {
- struct ref_iterator base;
-
- struct packed_ref_cache *packed_refs;
-
- /* The current position in the mmapped file: */
- const char *pos;
-
- /* The end of the mmapped file: */
- const char *eof;
-
- struct object_id oid, peeled;
-
- struct strbuf refname_buf;
-};
-
-static int mmapped_ref_iterator_advance(struct ref_iterator *ref_iterator)
-{
- struct mmapped_ref_iterator *iter =
- (struct mmapped_ref_iterator *)ref_iterator;
- const char *p = iter->pos, *eol;
-
- strbuf_reset(&iter->refname_buf);
-
- if (iter->pos == iter->eof)
- return ref_iterator_abort(ref_iterator);
-
- iter->base.flags = REF_ISPACKED;
-
- if (iter->eof - p < GIT_SHA1_HEXSZ + 2 ||
- parse_oid_hex(p, &iter->oid, &p) ||
- !isspace(*p++))
- die_invalid_line(iter->packed_refs->refs->path,
- iter->pos, iter->eof - iter->pos);
-
- eol = memchr(p, '\n', iter->eof - p);
- if (!eol)
- die_unterminated_line(iter->packed_refs->refs->path,
- iter->pos, iter->eof - iter->pos);
-
- strbuf_add(&iter->refname_buf, p, eol - p);
- iter->base.refname = iter->refname_buf.buf;
-
- if (check_refname_format(iter->base.refname, REFNAME_ALLOW_ONELEVEL)) {
- if (!refname_is_safe(iter->base.refname))
- die("packed refname is dangerous: %s",
- iter->base.refname);
- oidclr(&iter->oid);
- iter->base.flags |= REF_BAD_NAME | REF_ISBROKEN;
- }
- if (iter->packed_refs->peeled == PEELED_FULLY ||
- (iter->packed_refs->peeled == PEELED_TAGS &&
- starts_with(iter->base.refname, "refs/tags/")))
- iter->base.flags |= REF_KNOWS_PEELED;
-
- iter->pos = eol + 1;
-
- if (iter->pos < iter->eof && *iter->pos == '^') {
- p = iter->pos + 1;
- if (iter->eof - p < GIT_SHA1_HEXSZ + 1 ||
- parse_oid_hex(p, &iter->peeled, &p) ||
- *p++ != '\n')
- die_invalid_line(iter->packed_refs->refs->path,
- iter->pos, iter->eof - iter->pos);
- iter->pos = p;
-
- /*
- * Regardless of what the file header said, we
- * definitely know the value of *this* reference. But
- * we suppress it if the reference is broken:
- */
- if ((iter->base.flags & REF_ISBROKEN)) {
- oidclr(&iter->peeled);
- iter->base.flags &= ~REF_KNOWS_PEELED;
- } else {
- iter->base.flags |= REF_KNOWS_PEELED;
- }
- } else {
- oidclr(&iter->peeled);
- }
-
- return ITER_OK;
-}
-
-static int mmapped_ref_iterator_peel(struct ref_iterator *ref_iterator,
- struct object_id *peeled)
-{
- struct mmapped_ref_iterator *iter =
- (struct mmapped_ref_iterator *)ref_iterator;
-
- if ((iter->base.flags & REF_KNOWS_PEELED)) {
- oidcpy(peeled, &iter->peeled);
- return is_null_oid(&iter->peeled) ? -1 : 0;
- } else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) {
- return -1;
- } else {
- return !!peel_object(iter->oid.hash, peeled->hash);
- }
-}
-
-static int mmapped_ref_iterator_abort(struct ref_iterator *ref_iterator)
-{
- struct mmapped_ref_iterator *iter =
- (struct mmapped_ref_iterator *)ref_iterator;
-
- release_packed_ref_cache(iter->packed_refs);
- strbuf_release(&iter->refname_buf);
- base_ref_iterator_free(ref_iterator);
- return ITER_DONE;
-}
-
-static struct ref_iterator_vtable mmapped_ref_iterator_vtable = {
- mmapped_ref_iterator_advance,
- mmapped_ref_iterator_peel,
- mmapped_ref_iterator_abort
-};
-
-struct ref_iterator *mmapped_ref_iterator_begin(
- struct packed_ref_cache *packed_refs,
- const char *pos, const char *eof)
-{
- struct mmapped_ref_iterator *iter = xcalloc(1, sizeof(*iter));
- struct ref_iterator *ref_iterator = &iter->base;
-
- if (!packed_refs->buf)
- return empty_ref_iterator_begin();
-
- base_ref_iterator_init(ref_iterator, &mmapped_ref_iterator_vtable, 1);
-
- iter->packed_refs = packed_refs;
- acquire_packed_ref_cache(iter->packed_refs);
- iter->pos = pos;
- iter->eof = eof;
- strbuf_init(&iter->refname_buf, 0);
-
- iter->base.oid = &iter->oid;
-
- return ref_iterator;
-}
-
struct packed_ref_entry {
const char *start;
size_t len;
@@ -857,38 +706,120 @@ static int packed_read_raw_ref(struct ref_store *ref_store,
return 0;
}
+/*
+ * This value is set in `base.flags` if the peeled value of the
+ * current reference is known. In that case, `peeled` contains the
+ * correct peeled value for the reference, which might be `null_sha1`
+ * if the reference is not a tag or if it is broken.
+ */
+#define REF_KNOWS_PEELED 0x40
+
+/*
+ * An iterator over a packed-refs file that is currently mmapped.
+ */
struct packed_ref_iterator {
struct ref_iterator base;
- struct packed_ref_cache *cache;
- struct ref_iterator *iter0;
+ struct packed_ref_cache *packed_refs;
+
+ /* The current position in the mmapped file: */
+ const char *pos;
+
+ /* The end of the mmapped file: */
+ const char *eof;
+
+ struct object_id oid, peeled;
+
+ struct strbuf refname_buf;
+
unsigned int flags;
};
+static int next_record(struct packed_ref_iterator *iter)
+{
+ const char *p = iter->pos, *eol;
+
+ strbuf_reset(&iter->refname_buf);
+
+ if (iter->pos == iter->eof)
+ return ITER_DONE;
+
+ iter->base.flags = REF_ISPACKED;
+
+ if (iter->eof - p < GIT_SHA1_HEXSZ + 2 ||
+ parse_oid_hex(p, &iter->oid, &p) ||
+ !isspace(*p++))
+ die_invalid_line(iter->packed_refs->refs->path,
+ iter->pos, iter->eof - iter->pos);
+
+ eol = memchr(p, '\n', iter->eof - p);
+ if (!eol)
+ die_unterminated_line(iter->packed_refs->refs->path,
+ iter->pos, iter->eof - iter->pos);
+
+ strbuf_add(&iter->refname_buf, p, eol - p);
+ iter->base.refname = iter->refname_buf.buf;
+
+ if (check_refname_format(iter->base.refname, REFNAME_ALLOW_ONELEVEL)) {
+ if (!refname_is_safe(iter->base.refname))
+ die("packed refname is dangerous: %s",
+ iter->base.refname);
+ oidclr(&iter->oid);
+ iter->base.flags |= REF_BAD_NAME | REF_ISBROKEN;
+ }
+ if (iter->packed_refs->peeled == PEELED_FULLY ||
+ (iter->packed_refs->peeled == PEELED_TAGS &&
+ starts_with(iter->base.refname, "refs/tags/")))
+ iter->base.flags |= REF_KNOWS_PEELED;
+
+ iter->pos = eol + 1;
+
+ if (iter->pos < iter->eof && *iter->pos == '^') {
+ p = iter->pos + 1;
+ if (iter->eof - p < GIT_SHA1_HEXSZ + 1 ||
+ parse_oid_hex(p, &iter->peeled, &p) ||
+ *p++ != '\n')
+ die_invalid_line(iter->packed_refs->refs->path,
+ iter->pos, iter->eof - iter->pos);
+ iter->pos = p;
+
+ /*
+ * Regardless of what the file header said, we
+ * definitely know the value of *this* reference. But
+ * we suppress it if the reference is broken:
+ */
+ if ((iter->base.flags & REF_ISBROKEN)) {
+ oidclr(&iter->peeled);
+ iter->base.flags &= ~REF_KNOWS_PEELED;
+ } else {
+ iter->base.flags |= REF_KNOWS_PEELED;
+ }
+ } else {
+ oidclr(&iter->peeled);
+ }
+
+ return ITER_OK;
+}
+
static int packed_ref_iterator_advance(struct ref_iterator *ref_iterator)
{
struct packed_ref_iterator *iter =
(struct packed_ref_iterator *)ref_iterator;
int ok;
- while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
+ while ((ok = next_record(iter)) == ITER_OK) {
if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&
- ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)
+ ref_type(iter->base.refname) != REF_TYPE_PER_WORKTREE)
continue;
if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
- !ref_resolves_to_object(iter->iter0->refname,
- iter->iter0->oid,
- iter->iter0->flags))
+ !ref_resolves_to_object(iter->base.refname, &iter->oid,
+ iter->flags))
continue;
- iter->base.refname = iter->iter0->refname;
- iter->base.oid = iter->iter0->oid;
- iter->base.flags = iter->iter0->flags;
return ITER_OK;
}
- iter->iter0 = NULL;
if (ref_iterator_abort(ref_iterator) != ITER_DONE)
ok = ITER_ERROR;
@@ -901,7 +832,14 @@ static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator,
struct packed_ref_iterator *iter =
(struct packed_ref_iterator *)ref_iterator;
- return ref_iterator_peel(iter->iter0, peeled);
+ if ((iter->base.flags & REF_KNOWS_PEELED)) {
+ oidcpy(peeled, &iter->peeled);
+ return is_null_oid(&iter->peeled) ? -1 : 0;
+ } else if ((iter->base.flags & (REF_ISBROKEN | REF_ISSYMREF))) {
+ return -1;
+ } else {
+ return !!peel_object(iter->oid.hash, peeled->hash);
+ }
}
static int packed_ref_iterator_abort(struct ref_iterator *ref_iterator)
@@ -910,10 +848,8 @@ static int packed_ref_iterator_abort(struct ref_iterator *ref_iterator)
(struct packed_ref_iterator *)ref_iterator;
int ok = ITER_DONE;
- if (iter->iter0)
- ok = ref_iterator_abort(iter->iter0);
-
- release_packed_ref_cache(iter->cache);
+ strbuf_release(&iter->refname_buf);
+ release_packed_ref_cache(iter->packed_refs);
base_ref_iterator_free(ref_iterator);
return ok;
}
@@ -939,6 +875,11 @@ static struct ref_iterator *packed_ref_iterator_begin(
required_flags |= REF_STORE_ODB;
refs = packed_downcast(ref_store, required_flags, "ref_iterator_begin");
+ packed_refs = get_packed_ref_cache(refs);
+
+ if (!packed_refs->buf)
+ return empty_ref_iterator_begin();
+
iter = xcalloc(1, sizeof(*iter));
ref_iterator = &iter->base;
base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable, 1);
@@ -948,7 +889,7 @@ static struct ref_iterator *packed_ref_iterator_begin(
* the packed-ref cache is up to date with what is on disk,
* and re-reads it if not.
*/
- iter->cache = packed_refs = get_packed_ref_cache(refs);
+ iter->packed_refs = packed_refs;
acquire_packed_ref_cache(packed_refs);
if (prefix && *prefix)
@@ -956,8 +897,11 @@ static struct ref_iterator *packed_ref_iterator_begin(
else
start = packed_refs->buf + packed_refs->header_len;
- iter->iter0 = mmapped_ref_iterator_begin(packed_refs,
- start, packed_refs->eof);
+ iter->pos = start;
+ iter->eof = packed_refs->eof;
+ strbuf_init(&iter->refname_buf, 0);
+
+ iter->base.oid = &iter->oid;
iter->flags = flags;
--
2.14.1
next prev parent reply other threads:[~2017-09-19 6:23 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-19 6:22 [PATCH v2 00/21] Read `packed-refs` using mmap() Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 01/21] ref_iterator: keep track of whether the iterator output is ordered Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 02/21] prefix_ref_iterator: break when we leave the prefix Michael Haggerty
2017-09-20 20:25 ` Stefan Beller
2017-09-21 4:59 ` Jeff King
2017-09-21 17:29 ` Stefan Beller
2017-09-21 7:42 ` Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 03/21] packed_ref_cache: add a backlink to the associated `packed_ref_store` Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 04/21] die_unterminated_line(), die_invalid_line(): new functions Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 05/21] read_packed_refs(): use mmap to read the `packed-refs` file Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 06/21] read_packed_refs(): only check for a header at the top of the file Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 07/21] read_packed_refs(): make parsing of the header line more robust Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 08/21] read_packed_refs(): read references with minimal copying Michael Haggerty
2017-09-20 18:27 ` Jeff King
2017-09-21 7:34 ` Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 09/21] packed_ref_cache: remember the file-wide peeling state Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 10/21] mmapped_ref_iterator: add iterator over a packed-refs file Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 11/21] mmapped_ref_iterator_advance(): no peeled value for broken refs Michael Haggerty
2017-09-20 18:29 ` Jeff King
2017-09-19 6:22 ` [PATCH v2 12/21] packed-backend.c: reorder some definitions Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 13/21] packed_ref_cache: keep the `packed-refs` file mmapped if possible Michael Haggerty
2017-09-19 12:44 ` Michael Haggerty
2017-09-24 6:56 ` Junio C Hamano
2017-09-20 18:40 ` Jeff King
2017-09-20 18:51 ` Jeff King
2017-09-21 8:04 ` Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 14/21] read_packed_refs(): ensure that references are ordered when read Michael Haggerty
2017-09-20 18:50 ` Jeff King
2017-09-21 8:27 ` Michael Haggerty
2017-09-25 15:44 ` Johannes Schindelin
2017-09-19 6:22 ` [PATCH v2 15/21] packed_ref_iterator_begin(): iterate using `mmapped_ref_iterator` Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 16/21] packed_read_raw_ref(): read the reference from the mmapped buffer Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 17/21] ref_store: implement `refs_peel_ref()` generically Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 18/21] packed_ref_store: get rid of the `ref_cache` entirely Michael Haggerty
2017-09-19 6:22 ` [PATCH v2 19/21] ref_cache: remove support for storing peeled values Michael Haggerty
2017-09-19 6:22 ` Michael Haggerty [this message]
2017-09-19 6:22 ` [PATCH v2 21/21] packed-backend.c: rename a bunch of things and update comments Michael Haggerty
2017-09-19 19:53 ` [PATCH v2 00/21] Read `packed-refs` using mmap() Johannes Schindelin
2017-09-20 18:57 ` Jeff King
2017-09-25 15:55 ` Johannes Schindelin
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