From patchwork Tue Jan 26 16:01:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Derrick Stolee X-Patchwork-Id: 12047275 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B4A1C433DB for ; Tue, 26 Jan 2021 16:02:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF46E221EC for ; Tue, 26 Jan 2021 16:02:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404144AbhAZQCW (ORCPT ); Tue, 26 Jan 2021 11:02:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391058AbhAZQCM (ORCPT ); Tue, 26 Jan 2021 11:02:12 -0500 Received: from mail-wr1-x42a.google.com (mail-wr1-x42a.google.com [IPv6:2a00:1450:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DCB7C061A2E for ; Tue, 26 Jan 2021 08:01:31 -0800 (PST) Received: by mail-wr1-x42a.google.com with SMTP id 7so17030095wrz.0 for ; Tue, 26 Jan 2021 08:01:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=siZEtXbSOFXW3yL7TfR3RspVNwEahKzFKF1375HAfPw=; b=LY3nDHcmbUIdVlHmvjM4X2VnXOX/3IRYVtZfzL6HVDZkIq33iXdKFLifzbjKbupY59 UodG3QhrpB491jC/89lNbYRFUXUCfKxZNBuYMZ9VsgQj5cpUEU7v1XHTxItK8wUxFLAb DtPkBe/7IifytCjygYZHml7CcTg+Fdnecca+p86jBbQhqfd26TYJM3HsOOq7cItjODid IClL1Cl7U+UYn7mSfH2VJT6WiXE9ZPBqolg5cmtoRklvE1sGNyzkvJTlI4yZ2RVcxDOa U/s0f1cz+2I/tYCoABWDEs/5kFCVkHgpgw/+ZmOeNFjuqVW+F7+5P5QEMZ9MfgVj02Tw XuaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=siZEtXbSOFXW3yL7TfR3RspVNwEahKzFKF1375HAfPw=; b=ADQSqhufo79uemL+j/ysuhFwUHmDBrh/TuuUS6R/o4NJjlbic07SiT9EdY4a0CdLNu n/mFSBr1GWbh6ThuGBM86XhEaw1KFyhmX9KjmJIwn4MqjxWcqjPKxxl8SGM5bkkVWHdG xccCBohoDEhg11Cb6PC/9cYimWfLfyJa0gC++9OPu5SfTC7Aa3yDOtavYSY0/bHS3x0c F4PmzV23vpQYelLL9YVaGnOSlQBr1owgPhzeVWpktd4daBxTTze3tA1KGPuNGjcssBzB rUwkS7I1FjJfkR0qnaauPyGW12pdN0qVBIhKAqhGDStZKpdpY4dOzcLSsU0ptkuRYOhe m9NQ== X-Gm-Message-State: AOAM530+r+jhEmdgcVZ0sLHpVzLjRhhPn5vSOnV2qyGmpPluVIYHOOhg bZbRkoRgYIcLFbUCyQvgLcB+iN2GRUg= X-Google-Smtp-Source: ABdhPJwiNxVIn+8G8fy9752END+z+BBXmOYo0qMOOs7yd5sYmkxjStHZqpnJTt5gSMfaSKQx3dGQyQ== X-Received: by 2002:adf:dd45:: with SMTP id u5mr6767241wrm.392.1611676889965; Tue, 26 Jan 2021 08:01:29 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id a184sm3968026wme.35.2021.01.26.08.01.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Jan 2021 08:01:29 -0800 (PST) Message-Id: <9bd273f8c94fdb0c3adf8aedef3480ff5f4232b8.1611676886.git.gitgitgadget@gmail.com> In-Reply-To: References: Date: Tue, 26 Jan 2021 16:01:11 +0000 Subject: [PATCH 02/17] chunk-format: create chunk format write API Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: me@ttaylorr.com, gitster@pobox.com, l.s.r@web.de, szeder.dev@gmail.com, Derrick Stolee , Derrick Stolee Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Derrick Stolee From: Derrick Stolee In anticipation of combining the logic from the commit-graph and multi-pack-index file formats, create a new chunk-format API. Use a 'struct chunkfile' pointer to keep track of data that has been registered for writes. This struct is anonymous outside of chunk-format.c to ensure no user attempts to interfere with the data. The next change will use this API in commit-graph.c, but the general approach is: 1. initialize the chunkfile with init_chunkfile(f). 2. add chunks in the intended writing order with add_chunk(). 3. write any header information to the hashfile f. 4. write the chunkfile data using write_chunkfile(). 5. free the chunkfile struct using free_chunkfile(). Helped-by: Taylor Blau Signed-off-by: Derrick Stolee --- Makefile | 1 + chunk-format.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++ chunk-format.h | 20 +++++++++++ 3 files changed, 112 insertions(+) create mode 100644 chunk-format.c create mode 100644 chunk-format.h diff --git a/Makefile b/Makefile index 7b64106930a..50a7663841e 100644 --- a/Makefile +++ b/Makefile @@ -854,6 +854,7 @@ LIB_OBJS += bundle.o LIB_OBJS += cache-tree.o LIB_OBJS += chdir-notify.o LIB_OBJS += checkout.o +LIB_OBJS += chunk-format.o LIB_OBJS += color.o LIB_OBJS += column.o LIB_OBJS += combine-diff.o diff --git a/chunk-format.c b/chunk-format.c new file mode 100644 index 00000000000..2ce37ecc6bb --- /dev/null +++ b/chunk-format.c @@ -0,0 +1,91 @@ +#include "cache.h" +#include "chunk-format.h" +#include "csum-file.h" +#define CHUNK_LOOKUP_WIDTH 12 + +/* + * When writing a chunk-based file format, collect the chunks in + * an array of chunk_info structs. The size stores the _expected_ + * amount of data that will be written by write_fn. + */ +struct chunk_info { + uint32_t id; + uint64_t size; + chunk_write_fn write_fn; +}; + +struct chunkfile { + struct hashfile *f; + + struct chunk_info *chunks; + size_t chunks_nr; + size_t chunks_alloc; +}; + +struct chunkfile *init_chunkfile(struct hashfile *f) +{ + struct chunkfile *cf = xcalloc(1, sizeof(*cf)); + cf->f = f; + return cf; +} + +void free_chunkfile(struct chunkfile *cf) +{ + if (!cf) + return; + free(cf->chunks); + free(cf); +} + +int get_num_chunks(struct chunkfile *cf) +{ + return cf->chunks_nr; +} + +void add_chunk(struct chunkfile *cf, + uint64_t id, + chunk_write_fn fn, + size_t size) +{ + ALLOC_GROW(cf->chunks, cf->chunks_nr + 1, cf->chunks_alloc); + + cf->chunks[cf->chunks_nr].id = id; + cf->chunks[cf->chunks_nr].write_fn = fn; + cf->chunks[cf->chunks_nr].size = size; + cf->chunks_nr++; +} + +int write_chunkfile(struct chunkfile *cf, void *data) +{ + int i; + size_t cur_offset = cf->f->offset + cf->f->total; + + /* Add the table of contents to the current offset */ + cur_offset += (cf->chunks_nr + 1) * CHUNK_LOOKUP_WIDTH; + + for (i = 0; i < cf->chunks_nr; i++) { + hashwrite_be32(cf->f, cf->chunks[i].id); + hashwrite_be64(cf->f, cur_offset); + + cur_offset += cf->chunks[i].size; + } + + /* Trailing entry marks the end of the chunks */ + hashwrite_be32(cf->f, 0); + hashwrite_be64(cf->f, cur_offset); + + for (i = 0; i < cf->chunks_nr; i++) { + uint64_t start_offset = cf->f->total + cf->f->offset; + int result = cf->chunks[i].write_fn(cf->f, data); + + if (result) + return result; + + if (cf->f->total + cf->f->offset != start_offset + cf->chunks[i].size) + BUG("expected to write %"PRId64" bytes to chunk %"PRIx32", but wrote %"PRId64" instead", + cf->chunks[i].size, cf->chunks[i].id, + cf->f->total + cf->f->offset - start_offset); + } + + return 0; +} diff --git a/chunk-format.h b/chunk-format.h new file mode 100644 index 00000000000..bfaed672813 --- /dev/null +++ b/chunk-format.h @@ -0,0 +1,20 @@ +#ifndef CHUNK_FORMAT_H +#define CHUNK_FORMAT_H + +#include "git-compat-util.h" + +struct hashfile; +struct chunkfile; + +struct chunkfile *init_chunkfile(struct hashfile *f); +void free_chunkfile(struct chunkfile *cf); +int get_num_chunks(struct chunkfile *cf); +typedef int (*chunk_write_fn)(struct hashfile *f, + void *data); +void add_chunk(struct chunkfile *cf, + uint64_t id, + chunk_write_fn fn, + size_t size); +int write_chunkfile(struct chunkfile *cf, void *data); + +#endif