c-mini-vcs/commit.c at main · BaseMax/c-mini-vcs · GitHub

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#include "mvcs.h"

/* Write commit object */
int write_commit(const commit_t *commit, unsigned char *hash) {
    char buffer[4096];
    char tree_hex[HASH_HEX_SIZE];
    char parent_hex[HASH_HEX_SIZE];

    hash_to_hex(commit->tree_hash, tree_hex);

    int len;
    if (commit->has_parent) {
        hash_to_hex(commit->parent_hash, parent_hex);
        len = snprintf(buffer, sizeof(buffer),
                      "tree %s\nparent %s\nauthor %s\ntime %ld\n\n%s",
                      tree_hex, parent_hex, commit->author,
                      commit->timestamp, commit->message);
    } else {
        len = snprintf(buffer, sizeof(buffer),
                      "tree %s\nauthor %s\ntime %ld\n\n%s",
                      tree_hex, commit->author,
                      commit->timestamp, commit->message);
    }

    return write_object(OBJ_COMMIT, buffer, len, hash);
}

/* Read commit object */
int read_commit(const unsigned char *hash, commit_t *commit) {
    int type;
    void *data;
    size_t len;

    if (read_object(hash, &type, &data, &len) != 0 || type != OBJ_COMMIT) {
        return -1;
    }

    char *content = (char *)data;
    char tree_hex[HASH_HEX_SIZE];
    char parent_hex[HASH_HEX_SIZE];

    /* Parse commit data */
    commit->has_parent = 0;
    commit->message[0] = '\0';

    /* Find the blank line separating headers from message */
    char *msg_start = strstr(content, "\n\n");
    if (msg_start) {
        msg_start += 2; /* Skip the two newlines */
        strncpy(commit->message, msg_start, sizeof(commit->message) - 1);
        commit->message[sizeof(commit->message) - 1] = '\0';
        /* Remove trailing garbage by finding actual end */
        size_t msg_len = strlen(msg_start);
        if (msg_len < sizeof(commit->message)) {
            commit->message[msg_len] = '\0';
        }
    }

    /* Parse headers line by line */
    char *line_end;
    char *line = content;
    while (line && *line) {
        line_end = strchr(line, '\n');
        if (line_end) {
            *line_end = '\0';
        }

        if (strlen(line) == 0) {
            break; /* End of headers */
        }

        if (strncmp(line, "tree ", 5) == 0) {
            strncpy(tree_hex, line + 5, sizeof(tree_hex) - 1);
            tree_hex[sizeof(tree_hex) - 1] = '\0';
            hex_to_hash(tree_hex, commit->tree_hash);
        } else if (strncmp(line, "parent ", 7) == 0) {
            strncpy(parent_hex, line + 7, sizeof(parent_hex) - 1);
            parent_hex[sizeof(parent_hex) - 1] = '\0';
            hex_to_hash(parent_hex, commit->parent_hash);
            commit->has_parent = 1;
        } else if (strncmp(line, "author ", 7) == 0) {
            strncpy(commit->author, line + 7, sizeof(commit->author) - 1);
            commit->author[sizeof(commit->author) - 1] = '\0';
        } else if (strncmp(line, "time ", 5) == 0) {
            commit->timestamp = atol(line + 5);
        }

        if (!line_end) break;
        line = line_end + 1;
    }

    free(data);
    return 0;
}