From cbe566a0710b39691ca8f6cb6a764f6c553cd97b Mon Sep 17 00:00:00 2001 From: Jonathan Tan Date: Mon, 17 Aug 2020 21:01:31 -0700 Subject: [PATCH] negotiator/noop: add noop fetch negotiator Add a noop fetch negotiator. This is introduced to allow partial clones to skip the unneeded negotiation step when fetching missing objects using a "git fetch" subprocess. (The implementation of spawning a "git fetch" subprocess will be done in a subsequent patch.) But this can also be useful for end users, e.g. as a blunt fix for object corruption. Signed-off-by: Jonathan Tan Signed-off-by: Junio C Hamano --- Documentation/config/fetch.txt | 5 +++- Makefile | 1 + fetch-negotiator.c | 5 ++++ negotiator/noop.c | 44 ++++++++++++++++++++++++++++++++ negotiator/noop.h | 8 ++++++ repo-settings.c | 2 ++ repository.h | 1 + t/t5554-noop-fetch-negotiator.sh | 22 ++++++++++++++++ 8 files changed, 87 insertions(+), 1 deletion(-) create mode 100644 negotiator/noop.c create mode 100644 negotiator/noop.h create mode 100755 t/t5554-noop-fetch-negotiator.sh diff --git a/Documentation/config/fetch.txt b/Documentation/config/fetch.txt index b20394038d..6af6f5edb2 100644 --- a/Documentation/config/fetch.txt +++ b/Documentation/config/fetch.txt @@ -60,7 +60,10 @@ fetch.negotiationAlgorithm:: sent when negotiating the contents of the packfile to be sent by the server. Set to "skipping" to use an algorithm that skips commits in an effort to converge faster, but may result in a larger-than-necessary - packfile; The default is "default" which instructs Git to use the default algorithm + packfile; or set to "noop" to not send any information at all, which + will almost certainly result in a larger-than-necessary packfile, but + will skip the negotiation step. + The default is "default" which instructs Git to use the default algorithm that never skips commits (unless the server has acknowledged it or one of its descendants). If `feature.experimental` is enabled, then this setting defaults to "skipping". diff --git a/Makefile b/Makefile index 65f8cfb236..acdd2e356d 100644 --- a/Makefile +++ b/Makefile @@ -916,6 +916,7 @@ LIB_OBJS += mergesort.o LIB_OBJS += midx.o LIB_OBJS += name-hash.o LIB_OBJS += negotiator/default.o +LIB_OBJS += negotiator/noop.o LIB_OBJS += negotiator/skipping.o LIB_OBJS += notes-cache.o LIB_OBJS += notes-merge.o diff --git a/fetch-negotiator.c b/fetch-negotiator.c index 0a1357dc9d..57ed5784e1 100644 --- a/fetch-negotiator.c +++ b/fetch-negotiator.c @@ -2,6 +2,7 @@ #include "fetch-negotiator.h" #include "negotiator/default.h" #include "negotiator/skipping.h" +#include "negotiator/noop.h" #include "repository.h" void fetch_negotiator_init(struct repository *r, @@ -13,6 +14,10 @@ void fetch_negotiator_init(struct repository *r, skipping_negotiator_init(negotiator); return; + case FETCH_NEGOTIATION_NOOP: + noop_negotiator_init(negotiator); + return; + case FETCH_NEGOTIATION_DEFAULT: default: default_negotiator_init(negotiator); diff --git a/negotiator/noop.c b/negotiator/noop.c new file mode 100644 index 0000000000..60569b8350 --- /dev/null +++ b/negotiator/noop.c @@ -0,0 +1,44 @@ +#include "cache.h" +#include "noop.h" +#include "../commit.h" +#include "../fetch-negotiator.h" + +static void known_common(struct fetch_negotiator *n, struct commit *c) +{ + /* do nothing */ +} + +static void add_tip(struct fetch_negotiator *n, struct commit *c) +{ + /* do nothing */ +} + +static const struct object_id *next(struct fetch_negotiator *n) +{ + return NULL; +} + +static int ack(struct fetch_negotiator *n, struct commit *c) +{ + /* + * This negotiator does not emit any commits, so there is no commit to + * be acknowledged. If there is any ack, there is a bug. + */ + BUG("ack with noop negotiator, which does not emit any commits"); + return 0; +} + +static void release(struct fetch_negotiator *n) +{ + /* nothing to release */ +} + +void noop_negotiator_init(struct fetch_negotiator *negotiator) +{ + negotiator->known_common = known_common; + negotiator->add_tip = add_tip; + negotiator->next = next; + negotiator->ack = ack; + negotiator->release = release; + negotiator->data = NULL; +} diff --git a/negotiator/noop.h b/negotiator/noop.h new file mode 100644 index 0000000000..2b4ec5d07a --- /dev/null +++ b/negotiator/noop.h @@ -0,0 +1,8 @@ +#ifndef NEGOTIATOR_NOOP_H +#define NEGOTIATOR_NOOP_H + +struct fetch_negotiator; + +void noop_negotiator_init(struct fetch_negotiator *negotiator); + +#endif diff --git a/repo-settings.c b/repo-settings.c index 0918408b34..aa61a35338 100644 --- a/repo-settings.c +++ b/repo-settings.c @@ -39,6 +39,8 @@ void prepare_repo_settings(struct repository *r) if (!repo_config_get_string(r, "fetch.negotiationalgorithm", &strval)) { if (!strcasecmp(strval, "skipping")) r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING; + else if (!strcasecmp(strval, "noop")) + r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_NOOP; else r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_DEFAULT; } diff --git a/repository.h b/repository.h index 3c1f7d54bd..628c834367 100644 --- a/repository.h +++ b/repository.h @@ -23,6 +23,7 @@ enum fetch_negotiation_setting { FETCH_NEGOTIATION_NONE = 0, FETCH_NEGOTIATION_DEFAULT = 1, FETCH_NEGOTIATION_SKIPPING = 2, + FETCH_NEGOTIATION_NOOP = 3, }; struct repo_settings { diff --git a/t/t5554-noop-fetch-negotiator.sh b/t/t5554-noop-fetch-negotiator.sh new file mode 100755 index 0000000000..2ac7b5859e --- /dev/null +++ b/t/t5554-noop-fetch-negotiator.sh @@ -0,0 +1,22 @@ +#!/bin/sh + +test_description='test noop fetch negotiator' +. ./test-lib.sh + +test_expect_success 'noop negotiator does not emit any "have"' ' + rm -f trace && + + test_create_repo server && + test_commit -C server to_fetch && + + test_create_repo client && + test_commit -C client we_have && + + test_config -C client fetch.negotiationalgorithm noop && + GIT_TRACE_PACKET="$(pwd)/trace" git -C client fetch "$(pwd)/server" && + + ! grep "fetch> have" trace && + grep "fetch> done" trace +' + +test_done