root/patch-ids.c

DEFINITIONS

1. commit_patch_id
2. patch_id_access
3. patch_pos
4. init_patch_ids
5. free_patch_ids
6. add_commit
7. has_commit_patch_id
8. add_commit_patch_id

#include "cache.h"
#include "diff.h"
#include "commit.h"
#include "sha1-lookup.h"
#include "patch-ids.h"

static int commit_patch_id(struct commit *commit, struct diff_options *options,
                    unsigned char *sha1)
{
        if (commit->parents)
                diff_tree_sha1(commit->parents->item->object.sha1,
                               commit->object.sha1, "", options);
        else
                diff_root_tree_sha1(commit->object.sha1, "", options);
        diffcore_std(options);
        return diff_flush_patch_id(options, sha1);
}

static const unsigned char *patch_id_access(size_t index, void *table)
{
        struct patch_id **id_table = table;
        return id_table[index]->patch_id;
}

static int patch_pos(struct patch_id **table, int nr, const unsigned char *id)
{
        return sha1_pos(id, table, nr, patch_id_access);
}

#define BUCKET_SIZE 190 /* 190 * 21 = 3990, with slop close enough to 4K */
struct patch_id_bucket {
        struct patch_id_bucket *next;
        int nr;
        struct patch_id bucket[BUCKET_SIZE];
};

int init_patch_ids(struct patch_ids *ids)
{
        memset(ids, 0, sizeof(*ids));
        diff_setup(&ids->diffopts);
        DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
        diff_setup_done(&ids->diffopts);
        return 0;
}

int free_patch_ids(struct patch_ids *ids)
{
        struct patch_id_bucket *next, *patches;

        free(ids->table);
        for (patches = ids->patches; patches; patches = next) {
                next = patches->next;
                free(patches);
        }
        return 0;
}

static struct patch_id *add_commit(struct commit *commit,
                                   struct patch_ids *ids,
                                   int no_add)
{
        struct patch_id_bucket *bucket;
        struct patch_id *ent;
        unsigned char sha1[20];
        int pos;

        if (commit_patch_id(commit, &ids->diffopts, sha1))
                return NULL;
        pos = patch_pos(ids->table, ids->nr, sha1);
        if (0 <= pos)
                return ids->table[pos];
        if (no_add)
                return NULL;

        pos = -1 - pos;

        bucket = ids->patches;
        if (!bucket || (BUCKET_SIZE <= bucket->nr)) {
                bucket = xcalloc(1, sizeof(*bucket));
                bucket->next = ids->patches;
                ids->patches = bucket;
        }
        ent = &bucket->bucket[bucket->nr++];
        hashcpy(ent->patch_id, sha1);

        ALLOC_GROW(ids->table, ids->nr + 1, ids->alloc);
        if (pos < ids->nr)
                memmove(ids->table + pos + 1, ids->table + pos,
                        sizeof(ent) * (ids->nr - pos));
        ids->nr++;
        ids->table[pos] = ent;
        return ids->table[pos];
}

struct patch_id *has_commit_patch_id(struct commit *commit,
                                     struct patch_ids *ids)
{
        return add_commit(commit, ids, 1);
}

struct patch_id *add_commit_patch_id(struct commit *commit,
                                     struct patch_ids *ids)
{
        return add_commit(commit, ids, 0);
}