From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sun He Subject: [PATCH v4] Replace memcpy with hashcpy when dealing hash copy globally Date: Thu, 6 Mar 2014 17:11:24 +0800 Message-ID: <1394097084-3129-1-git-send-email-sunheehnus@gmail.com> Cc: mhagger@alum.mit.edu, pclouds@gmail.com, gitster@pobox.com, Sun He To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Thu Mar 06 10:13:32 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WLUMt-0006bH-H5 for gcvg-git-2@plane.gmane.org; Thu, 06 Mar 2014 10:13:31 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751049AbaCFJNZ (ORCPT ); Thu, 6 Mar 2014 04:13:25 -0500 Received: from mail-pd0-f170.google.com ([209.85.192.170]:51401 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919AbaCFJNV (ORCPT ); Thu, 6 Mar 2014 04:13:21 -0500 Received: by mail-pd0-f170.google.com with SMTP id v10so2297157pde.29 for ; Thu, 06 Mar 2014 01:13:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=175ITCaTSip7yTZJczixFie2jK5anmWCMCaEMQ+jOxI=; b=ODpY2i2wkVqPo6IGwTRGfeHjXoqDLZEn+pSgu9jtMJWt2YIAWkBcXZNxUIPZJBiB3i pz+9p/zlRphxsrOA74zNah4zSwypNHo7tQ7F3MJ+LkeRMfFfOusJ1RrV31zMepzQ7kAY nxPVzYWU93mKXwlaJLDJjq9jitPIXr28Fd7/c/50WifufUawtTB0M1n4cse8J+ptGviK P9XLdN6Fy/ik+JElkyC7e9/CoKAe8VwfksmkSxMMdELVSMVSeNdd9Gqr9XpNNzwwVkdv Vma2t89aCxyfmaOuJ485wMGiXPubdxB56ZKXyy/QBqTTEx29BQvxYELR32jRy6ivLUyE stBg== X-Received: by 10.68.171.229 with SMTP id ax5mr12854015pbc.125.1394097200190; Thu, 06 Mar 2014 01:13:20 -0800 (PST) Received: from ENIGMA.61.134.1.4 ([61.150.43.99]) by mx.google.com with ESMTPSA id hc4sm17513606pbc.29.2014.03.06.01.13.15 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Mar 2014 01:13:19 -0800 (PST) X-Mailer: git-send-email 1.9.0.138.g2de3478.dirty Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: hashcpy() can keep the abstraction of "object name" behind it. Use it instead of memcpy() with hard-coded 20-byte length when moving object names between pieces of memory. We can benefit from it, when we switch to another hash algorithm, eg. MD5, by just fixing the hashcpy(). Leave ppc/sha1.c as it is, because the function is about the SHA-1 hash algorithm whose output is and will always be 20-byte. Helped-by: Michael Haggerty Helped-by: Duy Nguyen Helped-by: Junio C Hamano Signed-off-by: Sun He --- PATCH v4 changed the reason why should take this patch as tutored by Junio C Hamano. Thanks to Junio C Hamano PATCH v3 delete the one-space indentation on each line of commit message as is suggested by Eric Sunshine. Thanks to Eric Sunshine. PATCH v2 leave ppc/sha1.c alone. The general rule is if cache.h or git-compat-util.h is included, it is the first #include, and system includes will be always in git-compat-tuil.h. via Duy Nguyen The change in PATCH v1 is not proper because I placed cache.h in the end. And adding it to the head is not a good way to achieve the goal, as is said above "---". Thanks to Duy Nguyen. Find the potential places with memcpy by the bash command: $ git grep 'memcpy.*20' Thanks to Junio C Hamano bundle.c | 2 +- grep.c | 2 +- pack-bitmap-write.c | 2 +- reflog-walk.c | 4 ++-- refs.c | 2 +- 5 files changed, 6 insertions(+), 6 deletions(-) diff --git a/bundle.c b/bundle.c index e99065c..7809fbb 100644 --- a/bundle.c +++ b/bundle.c @@ -19,7 +19,7 @@ static void add_to_ref_list(const unsigned char *sha1, const char *name, list->list = xrealloc(list->list, list->alloc * sizeof(list->list[0])); } - memcpy(list->list[list->nr].sha1, sha1, 20); + hashcpy(list->list[list->nr].sha1, sha1); list->list[list->nr].name = xstrdup(name); list->nr++; } diff --git a/grep.c b/grep.c index c668034..f5101f7 100644 --- a/grep.c +++ b/grep.c @@ -1650,7 +1650,7 @@ void grep_source_init(struct grep_source *gs, enum grep_source_type type, break; case GREP_SOURCE_SHA1: gs->identifier = xmalloc(20); - memcpy(gs->identifier, identifier, 20); + hashcpy(gs->identifier, identifier); break; case GREP_SOURCE_BUF: gs->identifier = NULL; diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c index 1218bef..5f1791a 100644 --- a/pack-bitmap-write.c +++ b/pack-bitmap-write.c @@ -530,7 +530,7 @@ void bitmap_writer_finish(struct pack_idx_entry **index, header.version = htons(default_version); header.options = htons(flags | options); header.entry_count = htonl(writer.selected_nr); - memcpy(header.checksum, writer.pack_checksum, 20); + hashcpy(header.checksum, writer.pack_checksum); sha1write(f, &header, sizeof(header)); dump_bitmap(f, writer.commits); diff --git a/reflog-walk.c b/reflog-walk.c index b2fbdb2..d490f7d 100644 --- a/reflog-walk.c +++ b/reflog-walk.c @@ -32,8 +32,8 @@ static int read_one_reflog(unsigned char *osha1, unsigned char *nsha1, sizeof(struct reflog_info)); } item = array->items + array->nr; - memcpy(item->osha1, osha1, 20); - memcpy(item->nsha1, nsha1, 20); + hashcpy(item->osha1, osha1); + hashcpy(item->nsha1, nsha1); item->email = xstrdup(email); item->timestamp = timestamp; item->tz = tz; diff --git a/refs.c b/refs.c index 89228e2..f90b7ea 100644 --- a/refs.c +++ b/refs.c @@ -1222,7 +1222,7 @@ static int resolve_gitlink_packed_ref(struct ref_cache *refs, if (ref == NULL) return -1; - memcpy(sha1, ref->u.value.sha1, 20); + hashcpy(sha1, ref->u.value.sha1); return 0; } -- 1.9.0.138.g2de3478.dirty