From: "Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: me@ttaylorr.com, gitster@pobox.com, l.s.r@web.de,
szeder.dev@gmail.com, Derrick Stolee <derrickstolee@github.com>,
Derrick Stolee <dstolee@microsoft.com>
Subject: [PATCH 12/17] chunk-format: create read chunk API
Date: Tue, 26 Jan 2021 16:01:21 +0000 [thread overview]
Message-ID: <e3475633e1d2e397c5095f34c23a19fccb2c8428.1611676886.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.848.git.1611676886.gitgitgadget@gmail.com>
From: Derrick Stolee <dstolee@microsoft.com>
Add the capability to read the table of contents, then pair the chunks
with necessary logic using read_chunk_fn pointers. Callers will be added
in future changes, but the typical outline will be:
1. initialize a 'struct chunkfile' with init_chunkfile(NULL).
2. call read_table_of_contents().
3. for each chunk to parse, call pair_chunk() with appropriate pointers.
4. call free_chunkfile() to clear the 'struct chunkfile' data.
We are re-using the anonymous 'struct chunkfile' data, as it is internal
to the chunk-format API. This gives it essentially two modes: write and
read. If the same struct instance was used for both reads and writes,
then there would be failures.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
chunk-format.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++
chunk-format.h | 21 +++++++++++++++++
2 files changed, 85 insertions(+)
diff --git a/chunk-format.c b/chunk-format.c
index 2ce37ecc6bb..674d31d5e58 100644
--- a/chunk-format.c
+++ b/chunk-format.c
@@ -12,6 +12,8 @@ struct chunk_info {
uint32_t id;
uint64_t size;
chunk_write_fn write_fn;
+
+ const void *start;
};
struct chunkfile {
@@ -89,3 +91,65 @@ int write_chunkfile(struct chunkfile *cf, void *data)
return 0;
}
+
+int read_table_of_contents(struct chunkfile *cf,
+ const unsigned char *mfile,
+ size_t mfile_size,
+ uint64_t toc_offset,
+ int toc_length)
+{
+ uint32_t chunk_id;
+ const unsigned char *table_of_contents = mfile + toc_offset;
+
+ ALLOC_GROW(cf->chunks, toc_length, cf->chunks_alloc);
+
+ while (toc_length--) {
+ uint64_t chunk_offset, next_chunk_offset;
+
+ chunk_id = get_be32(table_of_contents);
+ chunk_offset = get_be64(table_of_contents + 4);
+
+ if (!chunk_id) {
+ error(_("terminating chunk id appears earlier than expected"));
+ return 1;
+ }
+
+ table_of_contents += CHUNK_LOOKUP_WIDTH;
+ next_chunk_offset = get_be64(table_of_contents + 4);
+
+ if (next_chunk_offset < chunk_offset ||
+ next_chunk_offset > mfile_size - the_hash_algo->rawsz) {
+ error(_("improper chunk offset(s) %"PRIx64" and %"PRIx64""),
+ chunk_offset, next_chunk_offset);
+ return -1;
+ }
+
+ cf->chunks[cf->chunks_nr].id = chunk_id;
+ cf->chunks[cf->chunks_nr].start = mfile + chunk_offset;
+ cf->chunks[cf->chunks_nr].size = next_chunk_offset - chunk_offset;
+ cf->chunks_nr++;
+ }
+
+ chunk_id = get_be32(table_of_contents);
+ if (chunk_id) {
+ error(_("final chunk has non-zero id %"PRIx32""), chunk_id);
+ return -1;
+ }
+
+ return 0;
+}
+
+int pair_chunk(struct chunkfile *cf,
+ uint32_t chunk_id,
+ chunk_read_fn fn,
+ void *data)
+{
+ int i;
+
+ for (i = 0; i < cf->chunks_nr; i++) {
+ if (cf->chunks[i].id == chunk_id)
+ return fn(cf->chunks[i].start, cf->chunks[i].size, data);
+ }
+
+ return CHUNK_NOT_FOUND;
+}
diff --git a/chunk-format.h b/chunk-format.h
index bfaed672813..250e08b8e6a 100644
--- a/chunk-format.h
+++ b/chunk-format.h
@@ -17,4 +17,25 @@ void add_chunk(struct chunkfile *cf,
size_t size);
int write_chunkfile(struct chunkfile *cf, void *data);
+int read_table_of_contents(struct chunkfile *cf,
+ const unsigned char *mfile,
+ size_t mfile_size,
+ uint64_t toc_offset,
+ int toc_length);
+
+/*
+ * When reading a table of contents, we find the chunk with matching 'id'
+ * then call its read_fn to populate the necessary 'data' based on the
+ * chunk start and size.
+ */
+typedef int (*chunk_read_fn)(const unsigned char *chunk_start,
+ size_t chunk_size, void *data);
+
+
+#define CHUNK_NOT_FOUND (-2)
+int pair_chunk(struct chunkfile *cf,
+ uint32_t chunk_id,
+ chunk_read_fn fn,
+ void *data);
+
#endif
--
gitgitgadget
next prev parent reply other threads:[~2021-01-26 16:12 UTC|newest]
Thread overview: 120+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 16:01 [PATCH 00/17] Refactor chunk-format into an API Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 01/17] commit-graph: anonymize data in chunk_write_fn Derrick Stolee via GitGitGadget
2021-01-27 1:53 ` Chris Torek
2021-01-27 2:36 ` Taylor Blau
2021-01-26 16:01 ` [PATCH 02/17] chunk-format: create chunk format write API Derrick Stolee via GitGitGadget
2021-01-27 2:42 ` Taylor Blau
2021-01-27 13:49 ` Derrick Stolee
2021-01-26 16:01 ` [PATCH 03/17] commit-graph: use chunk-format " Derrick Stolee via GitGitGadget
2021-01-27 2:47 ` Taylor Blau
2021-01-26 16:01 ` [PATCH 04/17] midx: rename pack_info to write_midx_context Derrick Stolee via GitGitGadget
2021-01-27 2:49 ` Taylor Blau
2021-01-26 16:01 ` [PATCH 05/17] midx: use context in write_midx_pack_names() Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 06/17] midx: add entries to write_midx_context Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 07/17] midx: add pack_perm " Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 08/17] midx: add num_large_offsets " Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 09/17] midx: return success/failure in chunk write methods Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 10/17] midx: drop chunk progress during write Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 11/17] midx: use chunk-format API in write_midx_internal() Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` Derrick Stolee via GitGitGadget [this message]
2021-01-27 3:02 ` [PATCH 12/17] chunk-format: create read chunk API Taylor Blau
2021-01-26 16:01 ` [PATCH 13/17] commit-graph: use chunk-format read API Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 14/17] midx: " Derrick Stolee via GitGitGadget
2021-01-27 3:06 ` Taylor Blau
2021-01-27 13:50 ` Derrick Stolee
2021-01-26 16:01 ` [PATCH 15/17] midx: use 64-bit multiplication for chunk sizes Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 16/17] chunk-format: restore duplicate chunk checks Derrick Stolee via GitGitGadget
2021-01-26 16:01 ` [PATCH 17/17] chunk-format: add technical docs Derrick Stolee via GitGitGadget
2021-01-26 22:37 ` [PATCH 00/17] Refactor chunk-format into an API Junio C Hamano
2021-01-27 2:29 ` Taylor Blau
2021-01-27 15:01 ` [PATCH v2 " Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 01/17] commit-graph: anonymize data in chunk_write_fn Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 02/17] chunk-format: create chunk format write API Derrick Stolee via GitGitGadget
2021-02-04 21:24 ` Junio C Hamano
2021-02-04 22:40 ` Junio C Hamano
2021-02-05 11:37 ` Derrick Stolee
2021-02-05 19:25 ` Junio C Hamano
2021-01-27 15:01 ` [PATCH v2 03/17] commit-graph: use chunk-format " Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 04/17] midx: rename pack_info to write_midx_context Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 05/17] midx: use context in write_midx_pack_names() Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 06/17] midx: add entries to write_midx_context Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 07/17] midx: add pack_perm " Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 08/17] midx: add num_large_offsets " Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 09/17] midx: return success/failure in chunk write methods Derrick Stolee via GitGitGadget
2021-02-04 22:59 ` Junio C Hamano
2021-02-05 11:42 ` Derrick Stolee
2021-01-27 15:01 ` [PATCH v2 10/17] midx: drop chunk progress during write Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 11/17] midx: use chunk-format API in write_midx_internal() Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 12/17] chunk-format: create read chunk API Derrick Stolee via GitGitGadget
2021-02-04 23:40 ` Junio C Hamano
2021-02-05 12:19 ` Derrick Stolee
2021-02-05 19:37 ` Junio C Hamano
2021-02-08 22:26 ` Junio C Hamano
2021-02-09 1:33 ` Derrick Stolee
2021-02-09 20:47 ` Junio C Hamano
2021-01-27 15:01 ` [PATCH v2 13/17] commit-graph: use chunk-format read API Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 14/17] midx: " Derrick Stolee via GitGitGadget
2021-01-27 15:01 ` [PATCH v2 15/17] midx: use 64-bit multiplication for chunk sizes Derrick Stolee via GitGitGadget
2021-02-05 0:00 ` Junio C Hamano
2021-02-05 10:59 ` Chris Torek
2021-02-05 20:41 ` Junio C Hamano
2021-02-06 20:35 ` Chris Torek
2021-02-05 12:30 ` Derrick Stolee
2021-02-05 19:42 ` Junio C Hamano
2021-02-07 19:50 ` SZEDER Gábor
2021-02-08 5:41 ` Junio C Hamano
2021-01-27 15:01 ` [PATCH v2 16/17] chunk-format: restore duplicate chunk checks Derrick Stolee via GitGitGadget
2021-02-05 0:05 ` Junio C Hamano
2021-02-05 12:31 ` Derrick Stolee
2021-01-27 15:01 ` [PATCH v2 17/17] chunk-format: add technical docs Derrick Stolee via GitGitGadget
2021-02-05 0:15 ` Junio C Hamano
2021-01-27 16:03 ` [PATCH v2 00/17] Refactor chunk-format into an API Taylor Blau
2021-02-05 2:08 ` Junio C Hamano
2021-02-05 2:27 ` Derrick Stolee
2021-02-05 14:30 ` [PATCH v3 " Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 01/17] commit-graph: anonymize data in chunk_write_fn Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 02/17] chunk-format: create chunk format write API Derrick Stolee via GitGitGadget
2021-02-07 21:13 ` SZEDER Gábor
2021-02-08 13:44 ` Derrick Stolee
2021-02-11 19:43 ` SZEDER Gábor
2021-02-05 14:30 ` [PATCH v3 03/17] commit-graph: use chunk-format " Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 04/17] midx: rename pack_info to write_midx_context Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 05/17] midx: use context in write_midx_pack_names() Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 06/17] midx: add entries to write_midx_context Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 07/17] midx: add pack_perm " Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 08/17] midx: add num_large_offsets " Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 09/17] midx: return success/failure in chunk write methods Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 10/17] midx: drop chunk progress during write Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 11/17] midx: use chunk-format API in write_midx_internal() Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 12/17] chunk-format: create read chunk API Derrick Stolee via GitGitGadget
2021-02-07 20:20 ` SZEDER Gábor
2021-02-08 13:35 ` Derrick Stolee
2021-02-05 14:30 ` [PATCH v3 13/17] commit-graph: use chunk-format read API Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 14/17] midx: " Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 15/17] midx: use 64-bit multiplication for chunk sizes Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 16/17] chunk-format: restore duplicate chunk checks Derrick Stolee via GitGitGadget
2021-02-05 14:30 ` [PATCH v3 17/17] chunk-format: add technical docs Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 00/17] Refactor chunk-format into an API Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 01/17] commit-graph: anonymize data in chunk_write_fn Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 02/17] chunk-format: create chunk format write API Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 03/17] commit-graph: use chunk-format " Derrick Stolee via GitGitGadget
2021-02-24 16:52 ` SZEDER Gábor
2021-02-24 17:12 ` Taylor Blau
2021-02-24 17:52 ` Derrick Stolee
2021-02-24 19:44 ` Junio C Hamano
2021-02-18 14:07 ` [PATCH v4 04/17] midx: rename pack_info to write_midx_context Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 05/17] midx: use context in write_midx_pack_names() Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 06/17] midx: add entries to write_midx_context Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 07/17] midx: add pack_perm " Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 08/17] midx: add num_large_offsets " Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 09/17] midx: return success/failure in chunk write methods Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 10/17] midx: drop chunk progress during write Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 11/17] midx: use chunk-format API in write_midx_internal() Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 12/17] chunk-format: create read chunk API Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 13/17] commit-graph: use chunk-format read API Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 14/17] midx: " Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 15/17] midx: use 64-bit multiplication for chunk sizes Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 16/17] chunk-format: restore duplicate chunk checks Derrick Stolee via GitGitGadget
2021-02-18 14:07 ` [PATCH v4 17/17] chunk-format: add technical docs Derrick Stolee via GitGitGadget
2021-02-18 21:47 ` Junio C Hamano
2021-02-19 12:42 ` Derrick Stolee
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=e3475633e1d2e397c5095f34c23a19fccb2c8428.1611676886.git.gitgitgadget@gmail.com \
--to=gitgitgadget@gmail.com \
--cc=derrickstolee@github.com \
--cc=dstolee@microsoft.com \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
--cc=l.s.r@web.de \
--cc=me@ttaylorr.com \
--cc=szeder.dev@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).