From: Derrick Stolee <stolee@gmail.com>
To: Duy Nguyen <pclouds@gmail.com>
Cc: "Git Mailing List" <git@vger.kernel.org>,
"Stefan Beller" <sbeller@google.com>,
"Derrick Stolee" <dstolee@microsoft.com>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
"Jonathan Nieder" <jrnieder@gmail.com>,
"Jonathan Tan" <jonathantanmy@google.com>,
"Martin Fick" <mfick@codeaurora.org>
Subject: Re: [PATCH 06/23] midx: struct midxed_git and 'read' subcommand
Date: Wed, 20 Jun 2018 09:13:36 -0400 [thread overview]
Message-ID: <3827f4ce-7f78-6566-d9c8-1830afb3c09c@gmail.com> (raw)
In-Reply-To: <CACsJy8A3qVRXrQ9YiiN3Ggrcc5XFJWaWRrTbdO8E_48yRmzrqQ@mail.gmail.com>
On 6/7/2018 1:54 PM, Duy Nguyen wrote:
> On Thu, Jun 7, 2018 at 4:03 PM, Derrick Stolee <stolee@gmail.com> wrote:
>> As we build the multi-pack-index feature by adding chunks at a time,
>> we want to test that the data is being written correctly.
>>
>> Create struct midxed_git to store an in-memory representation of a
> A word play on 'packed_git'? Amusing. Some more descriptive name would
> be better though. midxed looks almost like random letters thrown
> together.
I'll use 'struct multi_pack_index'.
>
>> multi-pack-index and a memory-map of the binary file. Initialize this
>> struct in load_midxed_git(object_dir).
>> +static int read_midx_file(const char *object_dir)
>> +{
>> + struct midxed_git *m = load_midxed_git(object_dir);
>> +
>> + if (!m)
>> + return 0;
> This looks like an error case, please don't just return zero,
> typically used to say "success". I don't know if this command stays
> "for debugging purposes" until the end. Of course in that case it does
> not really matter.
It is intended for debugging and testing. Generally, it is not an error
to not have a MIDX in an object directory.
>> +struct midxed_git *load_midxed_git(const char *object_dir)
>> +{
>> + struct midxed_git *m;
>> + int fd;
>> + struct stat st;
>> + size_t midx_size;
>> + void *midx_map;
>> + const char *midx_name = get_midx_filename(object_dir);
> mem leak? This function returns allocated memory if I remember correctly.
>
>> +
>> + fd = git_open(midx_name);
>> + if (fd < 0)
>> + return NULL;
> do an error_errno() so we know what went wrong at least.
>
>> + if (fstat(fd, &st)) {
>> + close(fd);
>> + return NULL;
> same here, we should know why fstat() fails.
>
>> + }
>> + midx_size = xsize_t(st.st_size);
>> +
>> + if (midx_size < MIDX_MIN_SIZE) {
>> + close(fd);
>> + die("multi-pack-index file %s is too small", midx_name);
> _()
>
> The use of die() should be discouraged though. Many people still try
> (or wish) to libify code and new die() does not help. I think error()
> here would be enough then you can return NULL. Or you can go fancier
> and store the error string in a strbuf like refs code.
>
>> + }
>> +
>> + midx_map = xmmap(NULL, midx_size, PROT_READ, MAP_PRIVATE, fd, 0);
>> +
>> + m = xcalloc(1, sizeof(*m) + strlen(object_dir) + 1);
>> + strcpy(m->object_dir, object_dir);
>> + m->data = midx_map;
>> +
>> + m->signature = get_be32(m->data);
>> + if (m->signature != MIDX_SIGNATURE) {
>> + error("multi-pack-index signature %X does not match signature %X",
>> + m->signature, MIDX_SIGNATURE);
> _(). Maybe 0x%08x instead of %x
>
>> + goto cleanup_fail;
>> + }
>> +
>> + m->version = *(m->data + 4);
> m->data[4] instead? shorter and easier to understand.
>
> Same comment on "*(m->data + x)" and error() without _() for the rest.
>
>> + if (m->version != MIDX_VERSION) {
>> + error("multi-pack-index version %d not recognized",
>> + m->version);
> _()
>> + goto cleanup_fail;
>> + }
>> +
>> + m->hash_version = *(m->data + 5);
> m->data[5]
>
>> +cleanup_fail:
>> + FREE_AND_NULL(m);
>> + munmap(midx_map, midx_size);
>> + close(fd);
>> + exit(1);
> It's bad enough that you die() but exit() in this code seems too much.
> Please just return NULL and let the caller handle the error.
Will do.
>
>> diff --git a/midx.h b/midx.h
>> index 3a63673952..a1d18ed991 100644
>> --- a/midx.h
>> +++ b/midx.h
>> @@ -1,4 +1,13 @@
>> +#ifndef MIDX_H
>> +#define MIDX_H
>> +
>> +#include "git-compat-util.h"
>> #include "cache.h"
>> +#include "object-store.h"
> I don't really think you need object-store here (git-compat-util.h
> too). "struct mixed_git;" would be enough for load_midxed_git
> declaration below.
>
>> #include "packfile.h"
>>
>> +struct midxed_git *load_midxed_git(const char *object_dir);
>> +
>> int write_midx_file(const char *object_dir);
>> +
>> +#endif
>> diff --git a/object-store.h b/object-store.h
>> index d683112fd7..77cb82621a 100644
>> --- a/object-store.h
>> +++ b/object-store.h
>> @@ -84,6 +84,25 @@ struct packed_git {
>> char pack_name[FLEX_ARRAY]; /* more */
>> };
>>
>> +struct midxed_git {
>> + struct midxed_git *next;
> Do we really have multiple midx files?
There is one per object directory currently, but you may have one
locally and one in each of your alternates. I do need to double-check
that we populate this list later in the series. (And I'll remove it from
this commit and save it for when it is needed.)
>
>> +
>> + int fd;
>> +
>> + const unsigned char *data;
>> + size_t data_len;
>> +
>> + uint32_t signature;
>> + unsigned char version;
>> + unsigned char hash_version;
>> + unsigned char hash_len;
>> + unsigned char num_chunks;
>> + uint32_t num_packs;
>> + uint32_t num_objects;
>> +
>> + char object_dir[FLEX_ARRAY];
> Why do you need to keep object_dir when it could be easily retrieved
> when the repo is available?
>
>> +};
>> +
>> struct raw_object_store {
>> /*
>> * Path to the repository's object store.
next prev parent reply other threads:[~2018-06-20 13:13 UTC|newest]
Thread overview: 192+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-07 14:03 [PATCH 00/23] Multi-pack-index (MIDX) Derrick Stolee
2018-06-07 14:03 ` [PATCH 01/23] midx: add design document Derrick Stolee
2018-06-11 19:04 ` Stefan Beller
2018-06-18 18:48 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 02/23] midx: add midx format details to pack-format.txt Derrick Stolee
2018-06-11 19:19 ` Stefan Beller
2018-06-18 19:01 ` Derrick Stolee
2018-06-18 19:41 ` Stefan Beller
2018-06-07 14:03 ` [PATCH 03/23] midx: add midx builtin Derrick Stolee
2018-06-07 17:20 ` Duy Nguyen
2018-06-18 19:23 ` Derrick Stolee
2018-06-11 21:02 ` Stefan Beller
2018-06-18 19:40 ` Derrick Stolee
2018-06-18 19:55 ` Stefan Beller
2018-06-18 19:58 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 04/23] midx: add 'write' subcommand and basic wiring Derrick Stolee
2018-06-07 17:27 ` Duy Nguyen
2018-06-07 14:03 ` [PATCH 05/23] midx: write header information to lockfile Derrick Stolee
2018-06-07 17:35 ` Duy Nguyen
2018-06-12 15:00 ` Duy Nguyen
2018-06-19 12:54 ` Derrick Stolee
2018-06-19 14:59 ` Duy Nguyen
2018-06-19 15:24 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 06/23] midx: struct midxed_git and 'read' subcommand Derrick Stolee
2018-06-07 17:54 ` Duy Nguyen
2018-06-20 13:13 ` Derrick Stolee [this message]
2018-06-07 18:31 ` Duy Nguyen
2018-06-20 13:33 ` Derrick Stolee
2018-06-20 15:07 ` Duy Nguyen
2018-06-20 16:39 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 07/23] midx: expand test data Derrick Stolee
2018-06-07 14:03 ` [PATCH 08/23] midx: read packfiles from pack directory Derrick Stolee
2018-06-07 18:03 ` Duy Nguyen
2018-06-20 16:33 ` [PATCH] packfile: generalize pack directory list Derrick Stolee
2018-06-07 14:03 ` [PATCH 09/23] midx: write pack names in chunk Derrick Stolee
2018-06-07 18:26 ` Duy Nguyen
2018-06-21 15:25 ` Derrick Stolee
2018-06-21 17:38 ` Junio C Hamano
2018-06-22 18:25 ` Derrick Stolee
2018-06-22 18:31 ` Junio C Hamano
2018-06-22 18:32 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 10/23] midx: write a lookup into the pack names chunk Derrick Stolee
2018-06-09 16:43 ` Duy Nguyen
2018-06-21 17:23 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 11/23] midx: sort and deduplicate objects from packfiles Derrick Stolee
2018-06-09 17:07 ` Duy Nguyen
2018-06-21 17:54 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 12/23] midx: write object ids in a chunk Derrick Stolee
2018-06-09 17:25 ` Duy Nguyen
2018-06-07 14:03 ` [PATCH 13/23] midx: write object id fanout chunk Derrick Stolee
2018-06-09 17:28 ` Duy Nguyen
2018-06-21 19:49 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 14/23] midx: write object offsets Derrick Stolee
2018-06-09 17:41 ` Duy Nguyen
2018-06-07 14:03 ` [PATCH 15/23] midx: create core.midx config setting Derrick Stolee
2018-06-07 14:03 ` [PATCH 16/23] midx: prepare midxed_git struct Derrick Stolee
2018-06-09 17:47 ` Duy Nguyen
2018-06-07 14:03 ` [PATCH 17/23] midx: read objects from multi-pack-index Derrick Stolee
2018-06-09 17:56 ` Duy Nguyen
2018-06-21 20:03 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 18/23] midx: use midx in abbreviation calculations Derrick Stolee
2018-06-09 18:01 ` Duy Nguyen
2018-06-22 18:38 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 19/23] midx: use existing midx when writing new one Derrick Stolee
2018-06-07 14:03 ` [PATCH 20/23] midx: use midx in approximate_object_count Derrick Stolee
2018-06-09 18:03 ` Duy Nguyen
2018-06-22 18:39 ` Derrick Stolee
2018-06-07 14:03 ` [PATCH 21/23] midx: prevent duplicate packfile loads Derrick Stolee
2018-06-09 18:05 ` Duy Nguyen
2018-06-07 14:03 ` [PATCH 22/23] midx: use midx to find ref-deltas Derrick Stolee
2018-06-07 14:03 ` [PATCH 23/23] midx: clear midx on repack Derrick Stolee
2018-06-09 18:13 ` Duy Nguyen
2018-06-22 18:44 ` Derrick Stolee
2018-06-07 14:06 ` [PATCH 00/23] Multi-pack-index (MIDX) Derrick Stolee
2018-06-07 14:45 ` Ævar Arnfjörð Bjarmason
2018-06-07 14:54 ` Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 00/24] " Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 01/24] multi-pack-index: add design document Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 02/24] multi-pack-index: add format details Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 03/24] multi-pack-index: add builtin Derrick Stolee
2018-06-25 19:15 ` Junio C Hamano
2018-06-25 14:34 ` [PATCH v2 04/24] multi-pack-index: add 'write' verb Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 05/24] midx: write header information to lockfile Derrick Stolee
2018-06-25 19:19 ` Junio C Hamano
2018-07-05 19:13 ` Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 06/24] multi-pack-index: load into memory Derrick Stolee
2018-06-25 19:38 ` Junio C Hamano
2018-07-05 14:19 ` Derrick Stolee
2018-07-05 18:58 ` Eric Sunshine
2018-07-06 19:20 ` Junio C Hamano
2018-06-25 14:34 ` [PATCH v2 07/24] multi-pack-index: expand test data Derrick Stolee
2018-06-25 19:45 ` Junio C Hamano
2018-06-25 14:34 ` [PATCH v2 08/24] packfile: generalize pack directory list Derrick Stolee
2018-06-25 19:57 ` Junio C Hamano
2018-06-25 14:34 ` [PATCH v2 09/24] multi-pack-index: read packfile list Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 10/24] multi-pack-index: write pack names in chunk Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 11/24] midx: read pack names into array Derrick Stolee
2018-06-25 23:52 ` Eric Sunshine
2018-06-25 14:34 ` [PATCH v2 12/24] midx: sort and deduplicate objects from packfiles Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 13/24] midx: write object ids in a chunk Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 14/24] midx: write object id fanout chunk Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 15/24] midx: write object offsets Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 16/24] config: create core.multiPackIndex setting Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 17/24] midx: prepare midxed_git struct Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 18/24] midx: read objects from multi-pack-index Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 19/24] midx: use midx in abbreviation calculations Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 20/24] midx: use existing midx when writing new one Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 21/24] midx: use midx in approximate_object_count Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 22/24] midx: prevent duplicate packfile loads Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 23/24] packfile: skip loading index if in multi-pack-index Derrick Stolee
2018-06-25 14:34 ` [PATCH v2 24/24] midx: clear midx on repack Derrick Stolee
2018-07-06 0:52 ` [PATCH v3 00/24] Multi-pack-index (MIDX) Derrick Stolee
2018-07-06 0:52 ` [PATCH v3 01/24] multi-pack-index: add design document Derrick Stolee
2018-07-06 0:52 ` [PATCH v3 02/24] multi-pack-index: add format details Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 03/24] multi-pack-index: add builtin Derrick Stolee
2018-07-06 3:54 ` Eric Sunshine
2018-07-06 0:53 ` [PATCH v3 04/24] multi-pack-index: add 'write' verb Derrick Stolee
2018-07-06 4:07 ` Eric Sunshine
2018-07-06 0:53 ` [PATCH v3 05/24] midx: write header information to lockfile Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 06/24] multi-pack-index: load into memory Derrick Stolee
2018-07-06 4:19 ` Eric Sunshine
2018-07-06 5:18 ` Eric Sunshine
2018-07-09 19:08 ` Junio C Hamano
2018-07-12 16:06 ` Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 07/24] multi-pack-index: expand test data Derrick Stolee
2018-07-06 4:36 ` Eric Sunshine
2018-07-06 5:20 ` Eric Sunshine
2018-07-12 14:10 ` Derrick Stolee
2018-07-12 18:02 ` Eric Sunshine
2018-07-12 18:06 ` Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 08/24] packfile: generalize pack directory list Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 09/24] multi-pack-index: read packfile list Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 10/24] multi-pack-index: write pack names in chunk Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 11/24] midx: read pack names into array Derrick Stolee
2018-07-06 4:58 ` Eric Sunshine
2018-07-06 0:53 ` [PATCH v3 12/24] midx: sort and deduplicate objects from packfiles Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 13/24] midx: write object ids in a chunk Derrick Stolee
2018-07-06 5:04 ` Eric Sunshine
2018-07-06 0:53 ` [PATCH v3 14/24] midx: write object id fanout chunk Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 15/24] midx: write object offsets Derrick Stolee
2018-07-06 5:27 ` Eric Sunshine
2018-07-12 16:33 ` Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 16/24] config: create core.multiPackIndex setting Derrick Stolee
2018-07-06 5:39 ` Eric Sunshine
2018-07-12 13:19 ` Derrick Stolee
2018-07-12 16:30 ` Derrick Stolee
2018-07-11 9:48 ` SZEDER Gábor
2018-07-12 13:01 ` Derrick Stolee
2018-07-12 13:31 ` SZEDER Gábor
2018-07-12 15:40 ` Derrick Stolee
2018-07-12 17:29 ` Junio C Hamano
2018-07-06 0:53 ` [PATCH v3 17/24] midx: prepare midxed_git struct Derrick Stolee
2018-07-06 5:41 ` Eric Sunshine
2018-07-06 0:53 ` [PATCH v3 18/24] midx: read objects from multi-pack-index Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 19/24] midx: use midx in abbreviation calculations Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 20/24] midx: use existing midx when writing new one Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 21/24] midx: use midx in approximate_object_count Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 22/24] midx: prevent duplicate packfile loads Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 23/24] packfile: skip loading index if in multi-pack-index Derrick Stolee
2018-07-06 0:53 ` [PATCH v3 24/24] midx: clear midx on repack Derrick Stolee
2018-07-06 5:52 ` Eric Sunshine
2018-07-12 19:39 ` [PATCH v4 00/23] Multi-pack-index (MIDX) Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 01/23] multi-pack-index: add design document Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 02/23] multi-pack-index: add format details Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 03/23] multi-pack-index: add builtin Derrick Stolee
2018-07-20 18:22 ` Junio C Hamano
2018-07-20 22:15 ` brian m. carlson
2018-07-20 22:28 ` Junio C Hamano
2018-07-12 19:39 ` [PATCH v4 04/23] multi-pack-index: add 'write' verb Derrick Stolee
2018-07-12 22:56 ` Eric Sunshine
2018-07-12 19:39 ` [PATCH v4 05/23] midx: write header information to lockfile Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 06/23] multi-pack-index: load into memory Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 07/23] t5319: expand test data Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 08/23] packfile: generalize pack directory list Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 09/23] multi-pack-index: read packfile list Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 10/23] multi-pack-index: write pack names in chunk Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 11/23] midx: read pack names into array Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 12/23] midx: sort and deduplicate objects from packfiles Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 13/23] midx: write object ids in a chunk Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 14/23] midx: write object id fanout chunk Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 15/23] midx: write object offsets Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 16/23] config: create core.multiPackIndex setting Derrick Stolee
2018-07-12 21:05 ` Junio C Hamano
2018-07-13 0:50 ` Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 17/23] midx: read objects from multi-pack-index Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 18/23] midx: use midx in abbreviation calculations Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 19/23] midx: use existing midx when writing new one Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 20/23] midx: use midx in approximate_object_count Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 21/23] midx: prevent duplicate packfile loads Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 22/23] packfile: skip loading index if in multi-pack-index Derrick Stolee
2018-07-12 19:39 ` [PATCH v4 23/23] midx: clear midx on repack Derrick Stolee
2018-07-12 21:11 ` [PATCH v4 00/23] Multi-pack-index (MIDX) Junio C Hamano
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