mdb_dump.c

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/* mdb_dump.c - memory-mapped database dump tool */
/*
 * Copyright 2011-2018 Howard Chu, Symas Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted only as authorized by the OpenLDAP
 * Public License.
 *
 * A copy of this license is available in the file LICENSE in the
 * top-level directory of the distribution or, alternatively, at
 * <http://www.OpenLDAP.org/license.html>.
 */
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <signal.h>
#include "lmdb.h"
 
#ifdef _WIN32
#define Z   "I"
#else
#define Z   "z"
#endif
 
#define PRINT   1
static int mode;
 
typedef struct flagbit {
    int bit;
    char *name;
} flagbit;
 
flagbit dbflags[] = {
    { MDB_REVERSEKEY, "reversekey" },
    { MDB_DUPSORT, "dupsort" },
    { MDB_INTEGERKEY, "integerkey" },
    { MDB_DUPFIXED, "dupfixed" },
    { MDB_INTEGERDUP, "integerdup" },
    { MDB_REVERSEDUP, "reversedup" },
    { 0, NULL }
};
 
static volatile sig_atomic_t gotsig;
 
static void dumpsig( int sig )
{
    gotsig=1;
}
 
static const char hexc[] = "0123456789abcdef";
 
static void hex(unsigned char c)
{
    putchar(hexc[c >> 4]);
    putchar(hexc[c & 0xf]);
}
 
static void text(MDB_val *v)
{
    unsigned char *c, *end;
 
    putchar(' ');
    c = v->mv_data;
    end = c + v->mv_size;
    while (c < end) {
        if (isprint(*c)) {
            putchar(*c);
        } else {
            putchar('\\');
            hex(*c);
        }
        c++;
    }
    putchar('\n');
}
 
static void byte(MDB_val *v)
{
    unsigned char *c, *end;
 
    putchar(' ');
    c = v->mv_data;
    end = c + v->mv_size;
    while (c < end) {
        hex(*c++);
    }
    putchar('\n');
}
 
/* Dump in BDB-compatible format */
static int dumpit(MDB_txn *txn, MDB_dbi dbi, char *name)
{
    MDB_cursor *mc;
    MDB_stat ms;
    MDB_val key, data;
    MDB_envinfo info;
    unsigned int flags;
    int rc, i;
 
    rc = mdb_dbi_flags(txn, dbi, &flags);
    if (rc) return rc;
 
    rc = mdb_stat(txn, dbi, &ms);
    if (rc) return rc;
 
    rc = mdb_env_info(mdb_txn_env(txn), &info);
    if (rc) return rc;
 
    printf("VERSION=3\n");
    printf("format=%s\n", mode & PRINT ? "print" : "bytevalue");
    if (name)
        printf("database=%s\n", name);
    printf("type=btree\n");
    printf("mapsize=%" Z "u\n", info.me_mapsize);
    if (info.me_mapaddr)
        printf("mapaddr=%p\n", info.me_mapaddr);
    printf("maxreaders=%u\n", info.me_maxreaders);
 
    if (flags & MDB_DUPSORT)
        printf("duplicates=1\n");
 
    for (i=0; dbflags[i].bit; i++)
        if (flags & dbflags[i].bit)
            printf("%s=1\n", dbflags[i].name);
 
    printf("db_pagesize=%d\n", ms.ms_psize);
    printf("HEADER=END\n");
 
    rc = mdb_cursor_open(txn, dbi, &mc);
    if (rc) return rc;
 
    while ((rc = mdb_cursor_get(mc, &key, &data, MDB_NEXT) == MDB_SUCCESS)) {
        if (gotsig) {
            rc = EINTR;
            break;
        }
        if (mode & PRINT) {
            text(&key);
            text(&data);
        } else {
            byte(&key);
            byte(&data);
        }
    }
    printf("DATA=END\n");
    if (rc == MDB_NOTFOUND)
        rc = MDB_SUCCESS;
 
    return rc;
}
 
static void usage(char *prog)
{
    fprintf(stderr, "usage: %s [-V] [-f output] [-l] [-n] [-p] [-a|-s subdb] dbpath\n", prog);
    exit(EXIT_FAILURE);
}
 
int main(int argc, char *argv[])
{
    int i, rc;
    MDB_env *env;
    MDB_txn *txn;
    MDB_dbi dbi;
    char *prog = argv[0];
    char *envname;
    char *subname = NULL;
    int alldbs = 0, envflags = 0, list = 0;
 
    if (argc < 2) {
        usage(prog);
    }
 
    /* -a: dump main DB and all subDBs
     * -s: dump only the named subDB
     * -n: use NOSUBDIR flag on env_open
     * -p: use printable characters
     * -f: write to file instead of stdout
     * -V: print version and exit
     * (default) dump only the main DB
     */
    while ((i = getopt(argc, argv, "af:lnps:V")) != EOF) {
        switch(i) {
        case 'V':
            printf("%s\n", MDB_VERSION_STRING);
            exit(0);
            break;
        case 'l':
            list = 1;
            /*FALLTHROUGH*/;
        case 'a':
            if (subname)
                usage(prog);
            alldbs++;
            break;
        case 'f':
            if (freopen(optarg, "w", stdout) == NULL) {
                fprintf(stderr, "%s: %s: reopen: %s\n",
                    prog, optarg, strerror(errno));
                exit(EXIT_FAILURE);
            }
            break;
        case 'n':
            envflags |= MDB_NOSUBDIR;
            break;
        case 'p':
            mode |= PRINT;
            break;
        case 's':
            if (alldbs)
                usage(prog);
            subname = optarg;
            break;
        default:
            usage(prog);
        }
    }
 
    if (optind != argc - 1)
        usage(prog);
 
#ifdef SIGPIPE
    signal(SIGPIPE, dumpsig);
#endif
#ifdef SIGHUP
    signal(SIGHUP, dumpsig);
#endif
    signal(SIGINT, dumpsig);
    signal(SIGTERM, dumpsig);
 
    envname = argv[optind];
    rc = mdb_env_create(&env);
    if (rc) {
        fprintf(stderr, "mdb_env_create failed, error %d %s\n", rc, mdb_strerror(rc));
        return EXIT_FAILURE;
    }
 
    if (alldbs || subname) {
        mdb_env_set_maxdbs(env, 2);
    }
 
    rc = mdb_env_open(env, envname, envflags | MDB_RDONLY, 0664);
    if (rc) {
        fprintf(stderr, "mdb_env_open failed, error %d %s\n", rc, mdb_strerror(rc));
        goto env_close;
    }
 
    rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
    if (rc) {
        fprintf(stderr, "mdb_txn_begin failed, error %d %s\n", rc, mdb_strerror(rc));
        goto env_close;
    }
 
    rc = mdb_open(txn, subname, 0, &dbi);
    if (rc) {
        fprintf(stderr, "mdb_open failed, error %d %s\n", rc, mdb_strerror(rc));
        goto txn_abort;
    }
 
    if (alldbs) {
        MDB_cursor *cursor;
        MDB_val key;
        int count = 0;
 
        rc = mdb_cursor_open(txn, dbi, &cursor);
        if (rc) {
            fprintf(stderr, "mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
            goto txn_abort;
        }
        while ((rc = mdb_cursor_get(cursor, &key, NULL, MDB_NEXT_NODUP)) == 0) {
            char *str;
            MDB_dbi db2;
            if (memchr(key.mv_data, '\0', key.mv_size))
                continue;
            count++;
            str = malloc(key.mv_size+1);
            memcpy(str, key.mv_data, key.mv_size);
            str[key.mv_size] = '\0';
            rc = mdb_open(txn, str, 0, &db2);
            if (rc == MDB_SUCCESS) {
                if (list) {
                    printf("%s\n", str);
                    list++;
                } else {
                    rc = dumpit(txn, db2, str);
                    if (rc)
                        break;
                }
                mdb_close(env, db2);
            }
            free(str);
            if (rc) continue;
        }
        mdb_cursor_close(cursor);
        if (!count) {
            fprintf(stderr, "%s: %s does not contain multiple databases\n", prog, envname);
            rc = MDB_NOTFOUND;
        } else if (rc == MDB_NOTFOUND) {
            rc = MDB_SUCCESS;
        }
    } else {
        rc = dumpit(txn, dbi, subname);
    }
    if (rc && rc != MDB_NOTFOUND)
        fprintf(stderr, "%s: %s: %s\n", prog, envname, mdb_strerror(rc));
 
    mdb_close(env, dbi);
txn_abort:
    mdb_txn_abort(txn);
env_close:
    mdb_env_close(env);
 
    return rc ? EXIT_FAILURE : EXIT_SUCCESS;
}