/* MDBX usage example * * Do a line-by-line comparison of this and sample-bdb.txt */ /* * Copyright 2015-2021 Leonid Yuriev . * Copyright 2017 Ilya Shipitsin . * Copyright 2012-2015 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 * . */ #include "mdbx.h" #include #include #include #include int main(int argc, char *argv[]) { (void)argc; (void)argv; int rc; MDBX_env *env = NULL; MDBX_dbi dbi = 0; MDBX_val key, data; MDBX_txn *txn = NULL; MDBX_cursor *cursor = NULL; char sval[32]; printf("MDBX limits:\n"); #if UINTPTR_MAX > 0xffffFFFFul || ULONG_MAX > 0xffffFFFFul const double scale_factor = 1099511627776.0; const char *const scale_unit = "TiB"; #else const double scale_factor = 1073741824.0; const char *const scale_unit = "GiB"; #endif const size_t pagesize_min = mdbx_limits_pgsize_min(); const size_t pagesize_max = mdbx_limits_pgsize_max(); const size_t pagesize_default = mdbx_default_pagesize(); printf("\tPage size: a power of 2, minimum %zu, maximum %zu bytes," " default %zu bytes.\n", pagesize_min, pagesize_max, pagesize_default); printf("\tKey size: minimum %zu, maximum ≈¼ pagesize (%zu bytes for default" " %zuK pagesize, %zu bytes for %zuK pagesize).\n", (size_t)0, mdbx_limits_keysize_max(-1, MDBX_DB_DEFAULTS), pagesize_default / 1024, mdbx_limits_keysize_max(pagesize_max, MDBX_DB_DEFAULTS), pagesize_max / 1024); printf("\tValue size: minimum %zu, maximum %zu (0x%08zX) bytes for maps," " ≈¼ pagesize for multimaps (%zu bytes for default %zuK pagesize," " %zu bytes for %zuK pagesize).\n", (size_t)0, mdbx_limits_valsize_max(pagesize_min, MDBX_DB_DEFAULTS), mdbx_limits_valsize_max(pagesize_min, MDBX_DB_DEFAULTS), mdbx_limits_valsize_max(-1, MDBX_DUPSORT), pagesize_default / 1024, mdbx_limits_valsize_max(pagesize_max, MDBX_DUPSORT), pagesize_max / 1024); printf("\tWrite transaction size: up to %zu (0x%zX) pages (%f %s for default " "%zuK pagesize, %f %s for %zuK pagesize).\n", mdbx_limits_txnsize_max(pagesize_min) / pagesize_min, mdbx_limits_txnsize_max(pagesize_min) / pagesize_min, mdbx_limits_txnsize_max(-1) / scale_factor, scale_unit, pagesize_default / 1024, mdbx_limits_txnsize_max(pagesize_max) / scale_factor, scale_unit, pagesize_max / 1024); printf("\tDatabase size: up to %zu pages (%f %s for default %zuK " "pagesize, %f %s for %zuK pagesize).\n", mdbx_limits_dbsize_max(pagesize_min) / pagesize_min, mdbx_limits_dbsize_max(-1) / scale_factor, scale_unit, pagesize_default / 1024, mdbx_limits_dbsize_max(pagesize_max) / scale_factor, scale_unit, pagesize_max / 1024); printf("\tMaximum sub-databases: %u.\n", MDBX_MAX_DBI); printf("-----\n"); rc = mdbx_env_create(&env); if (rc != MDBX_SUCCESS) { fprintf(stderr, "mdbx_env_create: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } rc = mdbx_env_open(env, "./example-db", MDBX_NOSUBDIR | MDBX_COALESCE | MDBX_LIFORECLAIM, 0664); if (rc != MDBX_SUCCESS) { fprintf(stderr, "mdbx_env_open: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } rc = mdbx_txn_begin(env, NULL, 0, &txn); if (rc != MDBX_SUCCESS) { fprintf(stderr, "mdbx_txn_begin: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } rc = mdbx_dbi_open(txn, NULL, 0, &dbi); if (rc != MDBX_SUCCESS) { fprintf(stderr, "mdbx_dbi_open: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } key.iov_len = sizeof(int); key.iov_base = sval; data.iov_len = sizeof(sval); data.iov_base = sval; sprintf(sval, "%03x %d foo bar", 32, 3141592); rc = mdbx_put(txn, dbi, &key, &data, 0); if (rc != MDBX_SUCCESS) { fprintf(stderr, "mdbx_put: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } rc = mdbx_txn_commit(txn); if (rc) { fprintf(stderr, "mdbx_txn_commit: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } txn = NULL; rc = mdbx_txn_begin(env, NULL, MDBX_TXN_RDONLY, &txn); if (rc != MDBX_SUCCESS) { fprintf(stderr, "mdbx_txn_begin: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } rc = mdbx_cursor_open(txn, dbi, &cursor); if (rc != MDBX_SUCCESS) { fprintf(stderr, "mdbx_cursor_open: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } int found = 0; while ((rc = mdbx_cursor_get(cursor, &key, &data, MDBX_NEXT)) == 0) { printf("key: %p %.*s, data: %p %.*s\n", key.iov_base, (int)key.iov_len, (char *)key.iov_base, data.iov_base, (int)data.iov_len, (char *)data.iov_base); found += 1; } if (rc != MDBX_NOTFOUND || found == 0) { fprintf(stderr, "mdbx_cursor_get: (%d) %s\n", rc, mdbx_strerror(rc)); goto bailout; } else { rc = MDBX_SUCCESS; } bailout: if (cursor) mdbx_cursor_close(cursor); if (txn) mdbx_txn_abort(txn); if (dbi) mdbx_dbi_close(env, dbi); if (env) mdbx_env_close(env); return (rc != MDBX_SUCCESS) ? EXIT_FAILURE : EXIT_SUCCESS; }