[PATCH v2 5/8] commit-graph: not compatible with replace objects
Create new method commit_graph_compatible(r) to check if a given repository r is compatible with the commit-graph feature. Fill the method with a check to see if replace-objects exist. Test this interaction succeeds, including ignoring an existing commit-graph and failing to write a new commit-graph. However, we do ensure that we write a new commit-graph by setting read_replace_refs to 0, thereby ignoring the replace refs. Signed-off-by: Derrick Stolee --- builtin/commit-graph.c | 4 commit-graph.c | 21 + replace-object.c| 2 +- replace-object.h| 2 ++ t/t5318-commit-graph.sh | 22 ++ 5 files changed, 50 insertions(+), 1 deletion(-) diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c index 0bf0c48657..da737df321 100644 --- a/builtin/commit-graph.c +++ b/builtin/commit-graph.c @@ -120,6 +120,8 @@ static int graph_read(int argc, const char **argv) return 0; } +extern int read_replace_refs; + static int graph_write(int argc, const char **argv) { struct string_list *pack_indexes = NULL; @@ -150,6 +152,8 @@ static int graph_write(int argc, const char **argv) if (!opts.obj_dir) opts.obj_dir = get_object_directory(); + read_replace_refs = 0; + if (opts.reachable) { write_commit_graph_reachable(opts.obj_dir, opts.append); return 0; diff --git a/commit-graph.c b/commit-graph.c index b0a55ad128..2c01fa433f 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -13,6 +13,8 @@ #include "commit-graph.h" #include "object-store.h" #include "alloc.h" +#include "hashmap.h" +#include "replace-object.h" #define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */ #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */ @@ -56,6 +58,19 @@ static struct commit_graph *alloc_commit_graph(void) return g; } +extern int read_replace_refs; + +static int commit_graph_compatible(struct repository *r) +{ + if (read_replace_refs) { + prepare_replace_object(r); + if (hashmap_get_size(&r->objects->replace_map->map)) + return 0; + } + + return 1; +} + struct commit_graph *load_commit_graph_one(const char *graph_file) { void *graph_map; @@ -223,6 +238,9 @@ static int prepare_commit_graph(struct repository *r) */ return 0; + if (!commit_graph_compatible(r)) + return 0; + obj_dir = r->objects->objectdir; prepare_commit_graph_one(r, obj_dir); prepare_alt_odb(r); @@ -693,6 +711,9 @@ void write_commit_graph(const char *obj_dir, int num_extra_edges; struct commit_list *parent; + if (!commit_graph_compatible(the_repository)) + return; + oids.nr = 0; oids.alloc = approximate_object_count() / 4; diff --git a/replace-object.c b/replace-object.c index 3c17864eb7..9821f1477e 100644 --- a/replace-object.c +++ b/replace-object.c @@ -32,7 +32,7 @@ static int register_replace_ref(struct repository *r, return 0; } -static void prepare_replace_object(struct repository *r) +void prepare_replace_object(struct repository *r) { if (r->objects->replace_map) return; diff --git a/replace-object.h b/replace-object.h index 9345e105dd..16528df942 100644 --- a/replace-object.h +++ b/replace-object.h @@ -10,6 +10,8 @@ struct replace_object { struct object_id replacement; }; +void prepare_replace_object(struct repository *r); + /* * This internal function is only declared here for the benefit of * lookup_replace_object(). Please do not call it directly. diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh index 4f17d7701e..e0c3c60f66 100755 --- a/t/t5318-commit-graph.sh +++ b/t/t5318-commit-graph.sh @@ -259,6 +259,28 @@ test_expect_success 'check that gc computes commit-graph' ' test_cmp commit-graph-after-gc $objdir/info/commit-graph ' +test_expect_success 'replace-objects invalidates commit-graph' ' + cd "$TRASH_DIRECTORY" && + test_when_finished rm -rf replace && + git clone full replace && + ( + cd replace && + git commit-graph write --reachable && + test_path_is_file .git/objects/info/commit-graph && + git replace HEAD~1 HEAD~2 && + git -c core.commitGraph=false log >expect && + git -c core.commitGraph=true log >actual && + test_cmp expect actual && + git commit-graph write --reachable && + git -c core.commitGraph=false --no-replace-objects log >expect && + git -c core.commitGraph=true --no-replace-objects log >actual && + test_cmp expect actual && + rm -rf .git/objects/info/commit-graph && + git commit-graph write --reachable && + test_path_is_file .git/objects/info/commit-graph + )
Re: [PATCH v2 5/8] commit-graph: not compatible with replace objects
Derrick Stolee writes: > Create new method commit_graph_compatible(r) to check if a given > repository r is compatible with the commit-graph feature. Fill the > method with a check to see if replace-objects exist. Test this > interaction succeeds, including ignoring an existing commit-graph and > failing to write a new commit-graph. However, we do ensure that > we write a new commit-graph by setting read_replace_refs to 0, thereby > ignoring the replace refs. > > Signed-off-by: Derrick Stolee > --- > builtin/commit-graph.c | 4 > commit-graph.c | 21 + > replace-object.c| 2 +- > replace-object.h| 2 ++ > t/t5318-commit-graph.sh | 22 ++ > 5 files changed, 50 insertions(+), 1 deletion(-) > > diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c > index 0bf0c48657..da737df321 100644 > --- a/builtin/commit-graph.c > +++ b/builtin/commit-graph.c > @@ -120,6 +120,8 @@ static int graph_read(int argc, const char **argv) > return 0; > } > > +extern int read_replace_refs; > + Why do you need this (and also in commit-graph.c)? I thought cache.h includes it, which you can just make use of it. > +static int commit_graph_compatible(struct repository *r) > +{ > + if (read_replace_refs) { > + prepare_replace_object(r); > + if (hashmap_get_size(&r->objects->replace_map->map)) > + return 0; > + } > + > + return 1; > +} > diff --git a/replace-object.c b/replace-object.c > index 3c17864eb7..9821f1477e 100644 > --- a/replace-object.c > +++ b/replace-object.c > @@ -32,7 +32,7 @@ static int register_replace_ref(struct repository *r, > return 0; > } > > -static void prepare_replace_object(struct repository *r) > +void prepare_replace_object(struct repository *r) > { > if (r->objects->replace_map) > return; The way the new caller is written, I am wondering if this function should return "we are (or, are not) using the replace object feature", making it unnecessary for callers on the reading side to know about "read-replace-refs" external variable, for example. /* * To be called on-demand from codepaths that want to make * sure that replacement objects can be found as necessary. * * Return number of replacement defined for the repository, or * -1 when !read_replace_refs tells us not to use replacement * mechanism at all. */ int prepare_replace_object(struct repository *r) { if (!read_replace_refs) return -1; if (!r->objects->replace_map) { r->objects->replace_map = xmalloc(...); oidmap_init(r->objects->replace_map, 0); for_each_refplace_ref(r, register_...); } return hashmap_get_size(&r->objects->replace_map->map); } Then, the caller side can simply become something like: #define cgraph_compat(r) (prepare_replace_object(r) <= 0) There are various writers to read_replace_refs variable, but I think they should first be replaced with calls to something like: void use_replace_refs(struct repository *r, int enable); which allows us to hide the global variable and later make it per repository if we wanted to.
Re: [PATCH v2 5/8] commit-graph: not compatible with replace objects
On 8/21/2018 1:45 PM, Junio C Hamano wrote: Derrick Stolee writes: Create new method commit_graph_compatible(r) to check if a given repository r is compatible with the commit-graph feature. Fill the method with a check to see if replace-objects exist. Test this interaction succeeds, including ignoring an existing commit-graph and failing to write a new commit-graph. However, we do ensure that we write a new commit-graph by setting read_replace_refs to 0, thereby ignoring the replace refs. Signed-off-by: Derrick Stolee --- builtin/commit-graph.c | 4 commit-graph.c | 21 + replace-object.c| 2 +- replace-object.h| 2 ++ t/t5318-commit-graph.sh | 22 ++ 5 files changed, 50 insertions(+), 1 deletion(-) diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c index 0bf0c48657..da737df321 100644 --- a/builtin/commit-graph.c +++ b/builtin/commit-graph.c @@ -120,6 +120,8 @@ static int graph_read(int argc, const char **argv) return 0; } +extern int read_replace_refs; + Why do you need this (and also in commit-graph.c)? I thought cache.h includes it, which you can just make use of it. You're right. I don't know how I missed that. +static int commit_graph_compatible(struct repository *r) +{ + if (read_replace_refs) { + prepare_replace_object(r); + if (hashmap_get_size(&r->objects->replace_map->map)) + return 0; + } + + return 1; +} diff --git a/replace-object.c b/replace-object.c index 3c17864eb7..9821f1477e 100644 --- a/replace-object.c +++ b/replace-object.c @@ -32,7 +32,7 @@ static int register_replace_ref(struct repository *r, return 0; } -static void prepare_replace_object(struct repository *r) +void prepare_replace_object(struct repository *r) { if (r->objects->replace_map) return; The way the new caller is written, I am wondering if this function should return "we are (or, are not) using the replace object feature", making it unnecessary for callers on the reading side to know about "read-replace-refs" external variable, for example. /* * To be called on-demand from codepaths that want to make * sure that replacement objects can be found as necessary. * * Return number of replacement defined for the repository, or * -1 when !read_replace_refs tells us not to use replacement * mechanism at all. */ int prepare_replace_object(struct repository *r) { if (!read_replace_refs) return -1; if (!r->objects->replace_map) { r->objects->replace_map = xmalloc(...); oidmap_init(r->objects->replace_map, 0); for_each_refplace_ref(r, register_...); } return hashmap_get_size(&r->objects->replace_map->map); } This is a good idea. I can incorporate it into v3. Then, the caller side can simply become something like: #define cgraph_compat(r) (prepare_replace_object(r) <= 0) With the next two patches that add more conditions to commit_graph_compatible(), I'd prefer keeping it a method instead of a macro. There are various writers to read_replace_refs variable, but I think they should first be replaced with calls to something like: void use_replace_refs(struct repository *r, int enable); which allows us to hide the global variable and later make it per repository if we wanted to. I will incorporate this into v3 as well. Thanks, -Stolee