From: Stefan Xenos <sxenos@xxxxxxxxxx> A change table stores a list of changes, and supports efficient lookup from a commit hash to the list of changes that reference that commit directly. It can be used to look up content commits or metacommits at the head of a change, but does not support lookup of commits referenced as part of the commit history. Signed-off-by: Stefan Xenos <sxenos@xxxxxxxxxx> Signed-off-by: Chris Poucet <poucet@xxxxxxxxxx> --- Makefile | 1 + change-table.c | 164 +++++++++++++++++++++++++++++++++++++++++++++++++ change-table.h | 122 ++++++++++++++++++++++++++++++++++++ 3 files changed, 287 insertions(+) create mode 100644 change-table.c create mode 100644 change-table.h diff --git a/Makefile b/Makefile index b2bcc00c289..2b847e7e7de 100644 --- a/Makefile +++ b/Makefile @@ -913,6 +913,7 @@ LIB_OBJS += bulk-checkin.o LIB_OBJS += bundle-uri.o LIB_OBJS += bundle.o LIB_OBJS += cache-tree.o +LIB_OBJS += change-table.o LIB_OBJS += cbtree.o LIB_OBJS += chdir-notify.o LIB_OBJS += checkout.o diff --git a/change-table.c b/change-table.c new file mode 100644 index 00000000000..1d3d64b36d8 --- /dev/null +++ b/change-table.c @@ -0,0 +1,164 @@ +#include "cache.h" +#include "change-table.h" +#include "commit.h" +#include "ref-filter.h" +#include "metacommit-parser.h" + +void change_table_init(struct change_table *table) +{ + memset(table, 0, sizeof(*table)); + mem_pool_init(&table->memory_pool, 0); + oidmap_init(&table->oid_to_metadata_index, 0); + strmap_init(&table->refname_to_change_head); +} + +static void change_list_clear(struct change_list *change_list) { + strset_clear(&change_list->refnames); +} + +static void commit_change_list_entry_clear( + struct commit_change_list_entry *entry) { + change_list_clear(&entry->changes); +} + +void change_table_clear(struct change_table *table) +{ + struct oidmap_iter iter; + struct commit_change_list_entry *next; + for (next = oidmap_iter_first(&table->oid_to_metadata_index, &iter); + next; + next = oidmap_iter_next(&iter)) { + + commit_change_list_entry_clear(next); + } + + oidmap_free(&table->oid_to_metadata_index, 0); + strmap_clear(&table->refname_to_change_head, 0); + mem_pool_discard(&table->memory_pool, 0); +} + +static void add_head_to_commit(struct change_table *table, + const struct object_id *to_add, + const char *refname) +{ + struct commit_change_list_entry *entry; + + entry = oidmap_get(&table->oid_to_metadata_index, to_add); + if (!entry) { + entry = mem_pool_calloc(&table->memory_pool, 1, sizeof(*entry)); + oidcpy(&entry->entry.oid, to_add); + strset_init(&entry->changes.refnames); + oidmap_put(&table->oid_to_metadata_index, entry); + } + strset_add(&entry->changes.refnames, refname); +} + +void change_table_add(struct change_table *table, + const char *refname, + struct commit *to_add) +{ + struct change_head *new_head; + int metacommit_type; + + new_head = mem_pool_calloc(&table->memory_pool, 1, sizeof(*new_head)); + + oidcpy(&new_head->head, &to_add->object.oid); + + metacommit_type = get_metacommit_content(to_add, &new_head->content); + /* If to_add is not a metacommit then the content is to_add itself, + * otherwise it will have been set by the call to + * get_metacommit_content. + */ + if (metacommit_type == METACOMMIT_TYPE_NONE) + oidcpy(&new_head->content, &to_add->object.oid); + new_head->abandoned = (metacommit_type == METACOMMIT_TYPE_ABANDONED); + new_head->remote = starts_with(refname, "refs/remote/"); + new_head->hidden = starts_with(refname, "refs/hiddenmetas/"); + + strmap_put(&table->refname_to_change_head, refname, new_head); + + if (!oideq(&new_head->content, &new_head->head)) { + /* We also remember to link between refname and the content oid */ + add_head_to_commit(table, &new_head->content, refname); + } + add_head_to_commit(table, &new_head->head, refname); +} + +static void change_table_add_matching_filter(struct change_table *table, + struct repository* repo, + struct ref_filter *filter) +{ + int i; + struct ref_array matching_refs = { 0 }; + + filter_refs(&matching_refs, filter, filter->kind); + + /* + * Determine the object id for the latest content commit for each change. + * Fetch the commit at the head of each change ref. If it's a normal commit, + * that's the commit we want. If it's a metacommit, locate its content parent + * and use that. + */ + + for (i = 0; i < matching_refs.nr; i++) { + struct ref_array_item *item = matching_refs.items[i]; + struct commit *commit; + + commit = lookup_commit_reference(repo, &item->objectname); + if (!commit) { + BUG("Invalid commit for refs/meta: %s", item->refname); + } + change_table_add(table, item->refname, commit); + } + + ref_array_clear(&matching_refs); +} + +void change_table_add_all_visible(struct change_table *table, + struct repository* repo) +{ + struct ref_filter filter = { 0 }; + const char *name_patterns[] = {NULL}; + filter.kind = FILTER_REFS_CHANGES; + filter.name_patterns = name_patterns; + + change_table_add_matching_filter(table, repo, &filter); +} + +static int return_true_callback(const char *refname, void *cb_data) +{ + return 1; +} + +int change_table_has_change_referencing(struct change_table *table, + const struct object_id *referenced_commit_id) +{ + return for_each_change_referencing(table, referenced_commit_id, + return_true_callback, NULL); +} + +int for_each_change_referencing(struct change_table *table, + const struct object_id *referenced_commit_id, each_change_fn fn, void *cb_data) +{ + int ret; + struct commit_change_list_entry *ccl_entry; + struct hashmap_iter iter; + struct strmap_entry *entry; + + ccl_entry = oidmap_get(&table->oid_to_metadata_index, + referenced_commit_id); + /* If this commit isn't referenced by any changes, it won't be in the map */ + if (!ccl_entry) + return 0; + strset_for_each_entry(&ccl_entry->changes.refnames, &iter, entry) { + ret = fn(entry->key, cb_data); + if (ret != 0) break; + } + return ret; +} + +struct change_head* get_change_head(struct change_table *table, + const char* refname) +{ + return strmap_get(&table->refname_to_change_head, refname); +} diff --git a/change-table.h b/change-table.h new file mode 100644 index 00000000000..85c2fb80d18 --- /dev/null +++ b/change-table.h @@ -0,0 +1,122 @@ +#ifndef CHANGE_TABLE_H +#define CHANGE_TABLE_H + +#include "oidmap.h" +#include "strmap.h" + +struct commit; +struct ref_filter; + +/** + * This struct holds a set of change refs. + */ +struct change_list { + /** + * The refnames in this set. + * This field is private. Use for_each_change_in to read. + */ + struct strset refnames; +}; + +/** + * Holds information about the head of a single change. + */ +struct change_head { + /** + * The location pointed to by the head of the change. May be a commit or a + * metacommit. + */ + struct object_id head; + /** + * The content commit for the latest commit in the change. Always points to a + * real commit, never a metacommit. + */ + struct object_id content; + /** + * Abandoned: indicates that the content commit should be removed from the + * history. + * + * Hidden: indicates that the change is an inactive change from the + * hiddenmetas namespace. Such changes will be hidden from the user by + * default. + * + * Deleted: indicates that the change has been removed from the repository. + * That is the ref was deleted since the time this struct was created. Such + * entries should be ignored. + */ + unsigned int abandoned:1, + hidden:1, + remote:1, + deleted:1; +}; + +/** + * Holds the list of change refs whose content points to a particular content + * commit. + */ +struct commit_change_list_entry { + struct oidmap_entry entry; + struct change_list changes; +}; + +/** + * Holds information about the heads of each change, and permits efficient + * lookup from a commit to the changes that reference it directly. + * + * All fields should be considered private. Use the change_table functions + * to interact with this struct. + */ +struct change_table { + /** + * Memory pool for the objects allocated by the change table. + */ + struct mem_pool memory_pool; + /* Map object_id to commit_change_list_entry structs. */ + struct oidmap oid_to_metadata_index; + /** + * Map of refnames to change_head structure which are allocated from + * memory_pool. + */ + struct strmap refname_to_change_head; +}; + +extern void change_table_init(struct change_table *table); +extern void change_table_clear(struct change_table *table); + +/* Adds the given change head to the change_table struct */ +extern void change_table_add(struct change_table *table, + const char *refname, + struct commit *target); + +/** + * Adds the non-hidden local changes to the given change_table struct. + */ +extern void change_table_add_all_visible(struct change_table *table, + struct repository *repo); + +typedef int each_change_fn(const char *refname, void *cb_data); + +extern int change_table_has_change_referencing( + struct change_table *table, + const struct object_id *referenced_commit_id); + +/** + * Iterates over all changes that reference the given commit. For metacommits, + * this is the list of changes that point directly to that metacommit. + * For normal commits, this is the list of changes that have this commit as + * their latest content. + */ +extern int for_each_change_referencing( + struct change_table *table, + const struct object_id *referenced_commit_id, + each_change_fn fn, + void *cb_data); + +/** + * Returns the change head for the given refname. Returns NULL if no such change + * exists. + */ +extern struct change_head* get_change_head(struct change_table *table, + const char* refname); + +#endif -- gitgitgadget