From ec06283844a90c3e9440286401e9ad7d86daa5ae Mon Sep 17 00:00:00 2001 From: Jonathan Tan Date: Thu, 14 Jun 2018 15:54:28 -0700 Subject: fetch-pack: introduce negotiator API Introduce the new files fetch-negotiator.{h,c}, which contains an API behind which the details of negotiation are abstracted. Currently, only one algorithm is available: the existing one. This patch is written to be easily reviewed: static functions are moved verbatim from fetch-pack.c to negotiator/default.c, and it can be seen that the lines replaced by negotiator->X() calls are present in the X() functions respectively. Signed-off-by: Jonathan Tan Signed-off-by: Junio C Hamano --- negotiator/default.c | 176 +++++++++++++++++++++++++++++++++++++++++++++++++++ negotiator/default.h | 8 +++ 2 files changed, 184 insertions(+) create mode 100644 negotiator/default.c create mode 100644 negotiator/default.h (limited to 'negotiator') diff --git a/negotiator/default.c b/negotiator/default.c new file mode 100644 index 0000000000..382fc77722 --- /dev/null +++ b/negotiator/default.c @@ -0,0 +1,176 @@ +#include "cache.h" +#include "default.h" +#include "../commit.h" +#include "../fetch-negotiator.h" +#include "../prio-queue.h" +#include "../refs.h" +#include "../tag.h" + +/* Remember to update object flag allocation in object.h */ +#define COMMON (1U << 2) +#define COMMON_REF (1U << 3) +#define SEEN (1U << 4) +#define POPPED (1U << 5) + +static int marked; + +struct negotiation_state { + struct prio_queue rev_list; + int non_common_revs; +}; + +static void rev_list_push(struct negotiation_state *ns, + struct commit *commit, int mark) +{ + if (!(commit->object.flags & mark)) { + commit->object.flags |= mark; + + if (parse_commit(commit)) + return; + + prio_queue_put(&ns->rev_list, commit); + + if (!(commit->object.flags & COMMON)) + ns->non_common_revs++; + } +} + +static int clear_marks(const char *refname, const struct object_id *oid, + int flag, void *cb_data) +{ + struct object *o = deref_tag(parse_object(oid), refname, 0); + + if (o && o->type == OBJ_COMMIT) + clear_commit_marks((struct commit *)o, + COMMON | COMMON_REF | SEEN | POPPED); + return 0; +} + +/* + * This function marks a rev and its ancestors as common. + * In some cases, it is desirable to mark only the ancestors (for example + * when only the server does not yet know that they are common). + */ +static void mark_common(struct negotiation_state *ns, struct commit *commit, + int ancestors_only, int dont_parse) +{ + if (commit != NULL && !(commit->object.flags & COMMON)) { + struct object *o = (struct object *)commit; + + if (!ancestors_only) + o->flags |= COMMON; + + if (!(o->flags & SEEN)) + rev_list_push(ns, commit, SEEN); + else { + struct commit_list *parents; + + if (!ancestors_only && !(o->flags & POPPED)) + ns->non_common_revs--; + if (!o->parsed && !dont_parse) + if (parse_commit(commit)) + return; + + for (parents = commit->parents; + parents; + parents = parents->next) + mark_common(ns, parents->item, 0, + dont_parse); + } + } +} + +/* + * Get the next rev to send, ignoring the common. + */ +static const struct object_id *get_rev(struct negotiation_state *ns) +{ + struct commit *commit = NULL; + + while (commit == NULL) { + unsigned int mark; + struct commit_list *parents; + + if (ns->rev_list.nr == 0 || ns->non_common_revs == 0) + return NULL; + + commit = prio_queue_get(&ns->rev_list); + parse_commit(commit); + parents = commit->parents; + + commit->object.flags |= POPPED; + if (!(commit->object.flags & COMMON)) + ns->non_common_revs--; + + if (commit->object.flags & COMMON) { + /* do not send "have", and ignore ancestors */ + commit = NULL; + mark = COMMON | SEEN; + } else if (commit->object.flags & COMMON_REF) + /* send "have", and ignore ancestors */ + mark = COMMON | SEEN; + else + /* send "have", also for its ancestors */ + mark = SEEN; + + while (parents) { + if (!(parents->item->object.flags & SEEN)) + rev_list_push(ns, parents->item, mark); + if (mark & COMMON) + mark_common(ns, parents->item, 1, 0); + parents = parents->next; + } + } + + return &commit->object.oid; +} + +static void known_common(struct fetch_negotiator *n, struct commit *c) +{ + if (!(c->object.flags & SEEN)) { + rev_list_push(n->data, c, COMMON_REF | SEEN); + mark_common(n->data, c, 1, 1); + } +} + +static void add_tip(struct fetch_negotiator *n, struct commit *c) +{ + n->known_common = NULL; + rev_list_push(n->data, c, SEEN); +} + +static const struct object_id *next(struct fetch_negotiator *n) +{ + n->known_common = NULL; + n->add_tip = NULL; + return get_rev(n->data); +} + +static int ack(struct fetch_negotiator *n, struct commit *c) +{ + int known_to_be_common = !!(c->object.flags & COMMON); + mark_common(n->data, c, 0, 1); + return known_to_be_common; +} + +static void release(struct fetch_negotiator *n) +{ + clear_prio_queue(&((struct negotiation_state *)n->data)->rev_list); + FREE_AND_NULL(n->data); +} + +void default_negotiator_init(struct fetch_negotiator *negotiator) +{ + struct negotiation_state *ns; + negotiator->known_common = known_common; + negotiator->add_tip = add_tip; + negotiator->next = next; + negotiator->ack = ack; + negotiator->release = release; + negotiator->data = ns = xcalloc(1, sizeof(*ns)); + ns->rev_list.compare = compare_commits_by_commit_date; + + if (marked) + for_each_ref(clear_marks, NULL); + marked = 1; +} diff --git a/negotiator/default.h b/negotiator/default.h new file mode 100644 index 0000000000..d23a8f2fb8 --- /dev/null +++ b/negotiator/default.h @@ -0,0 +1,8 @@ +#ifndef NEGOTIATOR_DEFAULT_H +#define NEGOTIATOR_DEFAULT_H + +struct fetch_negotiator; + +void default_negotiator_init(struct fetch_negotiator *negotiator); + +#endif -- cgit v1.2.3