mdbx-tools: add mdbx_drop tool.

Change-Id: Ib7b32668c13fcef5951ff7250df57b3263e14d69

.gitignore

@@ -22,6 +22,7 @@ mdbx_example
 libmdbx.creator.user
 mdbx_chk
 mdbx_copy
+mdbx_drop
 mdbx_dump
 mdbx_load
 mdbx_stat

CMakeLists.txt

@@ -648,7 +648,7 @@ if(MDBX_BUILD_TOOLS)
     set(WINGETOPT_SRC "")
   endif()
 
-  foreach(TOOL mdbx_chk mdbx_copy mdbx_stat mdbx_dump mdbx_load)
+  foreach(TOOL mdbx_chk mdbx_copy mdbx_stat mdbx_dump mdbx_load mdbx_drop)
     add_executable(${TOOL} mdbx.h ${MDBX_SOURCE_DIR}/${TOOL}.c ${WINGETOPT_SRC})
     if(MDBX_C_STANDARD)
       set_target_properties(${TOOL} PROPERTIES
@@ -704,6 +704,7 @@ if(MDBX_BUILD_TOOLS)
     mdbx_copy
     mdbx_dump
     mdbx_load
+    mdbx_drop
     RUNTIME
     DESTINATION ${MDBX_TOOLS_INSTALL_DESTINATION}
     COMPONENT runtime)
@@ -718,6 +719,7 @@ if(MDBX_BUILD_TOOLS)
       "${MDBX_SOURCE_DIR}/man1/mdbx_copy.1"
       "${MDBX_SOURCE_DIR}/man1/mdbx_dump.1"
       "${MDBX_SOURCE_DIR}/man1/mdbx_load.1"
+      "${MDBX_SOURCE_DIR}/man1/mdbx_drop.1"
       DESTINATION ${MDBX_MAN_INSTALL_DESTINATION}
       COMPONENT doc)
   endif()

ChangeLog.md

@@ -27,6 +27,7 @@ New features:
    of grow step and shrink threshold when huge ones (https://github.com/erthink/libmdbx/issues/166).
    To minimize the impact on compatibility, only the odd values inside the upper half
    of the range (i.e. 32769..65533) are used for the new representation.
+ - Added the `mdbx_drop` similar to LMDB command-line tool to purge or delete (sub)database(s).
 
 Fixes:
 

GNUmakefile

@@ -57,8 +57,8 @@ SO_SUFFIX  := $(shell $(uname2sosuffix))
 
 HEADERS    := mdbx.h mdbx.h++
 LIBRARIES  := libmdbx.a libmdbx.$(SO_SUFFIX)
-TOOLS      := mdbx_stat mdbx_copy mdbx_dump mdbx_load mdbx_chk
-MANPAGES   := mdbx_stat.1 mdbx_copy.1 mdbx_dump.1 mdbx_load.1 mdbx_chk.1
+TOOLS      := mdbx_stat mdbx_copy mdbx_dump mdbx_load mdbx_chk mdbx_drop
+MANPAGES   := mdbx_stat.1 mdbx_copy.1 mdbx_dump.1 mdbx_load.1 mdbx_chk.1 mdbx_drop.1
 
 .PHONY: mdbx all install clean
 

src/man1/mdbx_chk.1

@@ -94,5 +94,6 @@ if no quiet mode was requested.
 .BR mdbx_copy (1),
 .BR mdbx_dump (1),
 .BR mdbx_load (1)
+.BR mdbx_drop (1)
 .SH AUTHOR
 Leonid Yuriev <https://github.com/erthink>

src/man1/mdbx_copy.1

@@ -62,6 +62,7 @@ free during copying cannot be reused until the copy is done.
 .BR mdbx_chk (1),
 .BR mdbx_stat (1),
 .BR mdbx_load (1)
+.BR mdbx_drop (1)
 .SH AUTHOR
 Howard Chu of Symas Corporation <http://www.symas.com>,
 Leonid Yuriev <https://github.com/erthink>

src/man1/mdbx_drop.1

@@ -0,0 +1,48 @@
+.\" Copyright 2021 Leonid Yuriev <leo@yuriev.ru>.
+.\" Copyright 2014-2021 Howard Chu, Symas Corp. All Rights Reserved.
+.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
+.TH MDBX_DROP 1 "2021-02-02" "MDBX 0.9.3"
+.SH NAME
+mdbx_drop \- MDBX database delete tool
+.SH SYNOPSIS
+.B mdbx_drop
+[\c
+.BR \-V ]
+[\c
+.BR \-d ]
+[\c
+.BI \-s \ subdb\fR]
+[\c
+.BR \-n ]
+.BR \ dbpath
+.SH DESCRIPTION
+The
+.B mdbx_drop
+utility empties or deletes a database in the specified
+environment.
+.SH OPTIONS
+.TP
+.BR \-V
+Write the library version number to the standard output, and exit.
+.TP
+.BR \-d
+Delete the specified database, don't just empty it.
+.TP
+.BR \-s \ subdb
+Operate on a specific subdatabase. If no database is specified, only the main database is dropped.
+.TP
+.BR \-n
+Dump an MDBX database which does not use subdirectories.
+This is legacy option. For now MDBX handles this automatically.
+
+.SH DIAGNOSTICS
+Exit status is zero if no errors occur.
+Errors result in a non-zero exit status and
+a diagnostic message being written to standard error.
+.SH "SEE ALSO"
+.BR mdbx_load (1),
+.BR mdbx_copy (1),
+.BR mdbx_chk (1),
+.BR mdbx_stat (1)
+.SH AUTHOR
+Howard Chu of Symas Corporation <http://www.symas.com>

src/man1/mdbx_dump.1

@@ -88,6 +88,7 @@ utility to load the database using the correct comparison functions.
 .BR mdbx_copy (1),
 .BR mdbx_chk (1),
 .BR mdbx_stat (1)
+.BR mdbx_drop (1)
 .SH AUTHOR
 Howard Chu of Symas Corporation <http://www.symas.com>,
 Leonid Yuriev <https://github.com/erthink>

src/man1/mdbx_load.1

@@ -99,6 +99,7 @@ a diagnostic message being written to standard error.
 .BR mdbx_chk (1),
 .BR mdbx_stat (1),
 .BR mdbx_copy (1)
+.BR mdbx_drop (1)
 .SH AUTHOR
 Howard Chu of Symas Corporation <http://www.symas.com>,
 Leonid Yuriev <https://github.com/erthink>

src/man1/mdbx_stat.1

@@ -73,6 +73,7 @@ a diagnostic message being written to standard error.
 .BR mdbx_copy (1),
 .BR mdbx_dump (1),
 .BR mdbx_load (1)
+.BR mdbx_drop (1)
 .SH AUTHOR
 Howard Chu of Symas Corporation <http://www.symas.com>,
 Leonid Yuriev <https://github.com/erthink>

src/mdbx_drop.c

@@ -0,0 +1,187 @@
+/* mdbx_drop.c - memory-mapped database delete tool */
+
+/*
+ * Copyright 2021 Leonid Yuriev <leo@yuriev.ru>
+ * and other libmdbx authors: please see AUTHORS file.
+ *
+ * Copyright 2016-2021 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>. */
+
+#ifdef _MSC_VER
+#if _MSC_VER > 1800
+#pragma warning(disable : 4464) /* relative include path contains '..' */
+#endif
+#pragma warning(disable : 4996) /* The POSIX name is deprecated... */
+#endif                          /* _MSC_VER (warnings) */
+
+#define MDBX_TOOLS /* Avoid using internal mdbx_assert() */
+#include "internals.h"
+
+#include <ctype.h>
+
+#if defined(_WIN32) || defined(_WIN64)
+#include "wingetopt.h"
+
+static volatile BOOL user_break;
+static BOOL WINAPI ConsoleBreakHandlerRoutine(DWORD dwCtrlType) {
+  (void)dwCtrlType;
+  user_break = true;
+  return true;
+}
+
+#else /* WINDOWS */
+
+static volatile sig_atomic_t user_break;
+static void signal_handler(int sig) {
+  (void)sig;
+  user_break = 1;
+}
+
+#endif /* !WINDOWS */
+
+static char *prog;
+bool quiet = false;
+static void usage(void) {
+  fprintf(stderr, "usage: %s [-V] [-q] [-d] [-s name] dbpath\n", prog);
+  exit(EXIT_FAILURE);
+  fprintf(stderr,
+          "usage: %s "
+          "[-V] [-q] [-a] [-f file] [-s name] [-N] [-p] [-T] [-r] [-n] dbpath\n"
+          "  -V\t\tprint version and exit\n"
+          "  -q\t\tbe quiet\n"
+          "  -d\t\tdelete the specified database, don't just empty it\n",
+          prog);
+  exit(EXIT_FAILURE);
+}
+
+static void error(const char *func, int rc) {
+  if (!quiet)
+    fprintf(stderr, "%s: %s() error %d %s\n", prog, func, rc,
+            mdbx_strerror(rc));
+}
+
+int main(int argc, char *argv[]) {
+  int i, rc;
+  MDBX_env *env;
+  MDBX_txn *txn;
+  MDBX_dbi dbi;
+  char *envname = nullptr;
+  char *subname = nullptr;
+  int envflags = MDBX_ACCEDE;
+  bool delete = false;
+
+  prog = argv[0];
+  if (argc < 2)
+    usage();
+
+  /* -d: delete the db, don't just empty it
+   * -s: drop the named subDB
+   * -V: print version and exit
+   * (default) empty the main DB */
+  while ((i = getopt(argc, argv, "ds:nV")) != EOF) {
+    switch (i) {
+    case 'V':
+      printf("mdbx_drop version %d.%d.%d.%d\n"
+             " - source: %s %s, commit %s, tree %s\n"
+             " - anchor: %s\n"
+             " - build: %s for %s by %s\n"
+             " - flags: %s\n"
+             " - options: %s\n",
+             mdbx_version.major, mdbx_version.minor, mdbx_version.release,
+             mdbx_version.revision, mdbx_version.git.describe,
+             mdbx_version.git.datetime, mdbx_version.git.commit,
+             mdbx_version.git.tree, mdbx_sourcery_anchor, mdbx_build.datetime,
+             mdbx_build.target, mdbx_build.compiler, mdbx_build.flags,
+             mdbx_build.options);
+      return EXIT_SUCCESS;
+    case 'd':
+      delete = true;
+      break;
+    case 'n':
+      envflags |= MDBX_NOSUBDIR;
+      break;
+    case 's':
+      subname = optarg;
+      break;
+    default:
+      usage();
+    }
+  }
+
+  if (optind != argc - 1)
+    usage();
+
+#if defined(_WIN32) || defined(_WIN64)
+  SetConsoleCtrlHandler(ConsoleBreakHandlerRoutine, true);
+#else
+#ifdef SIGPIPE
+  signal(SIGPIPE, signal_handler);
+#endif
+#ifdef SIGHUP
+  signal(SIGHUP, signal_handler);
+#endif
+  signal(SIGINT, signal_handler);
+  signal(SIGTERM, signal_handler);
+#endif /* !WINDOWS */
+
+  envname = argv[optind];
+  if (!quiet)
+    printf("mdbx_drop %s (%s, T-%s)\nRunning for %s/%s...\n",
+           mdbx_version.git.describe, mdbx_version.git.datetime,
+           mdbx_version.git.tree, envname, subname ? subname : "@MAIN");
+  fflush(nullptr);
+
+  rc = mdbx_env_create(&env);
+  if (rc) {
+    error("mdbx_env_create", rc);
+    return EXIT_FAILURE;
+  }
+
+  mdbx_env_set_maxdbs(env, 2);
+
+  rc = mdbx_env_open(env, envname, envflags, 0664);
+  if (rc) {
+    error("mdbx_env_open", rc);
+    goto env_close;
+  }
+
+  rc = mdbx_txn_begin(env, NULL, 0, &txn);
+  if (rc) {
+    error("mdbx_txn_begin", rc);
+    goto env_close;
+  }
+
+  rc = mdbx_dbi_open(txn, subname, 0, &dbi);
+  if (rc) {
+    error("mdbx_open failed", rc);
+    goto txn_abort;
+  }
+
+  rc = mdbx_drop(txn, dbi, delete);
+  if (rc) {
+    error("mdbx_drop failed", rc);
+    goto txn_abort;
+  }
+  rc = mdbx_txn_commit(txn);
+  if (rc) {
+    error("mdbx_txn_commit failed", rc);
+    goto txn_abort;
+  }
+  txn = nullptr;
+
+txn_abort:
+  if (txn)
+    mdbx_txn_abort(txn);
+env_close:
+  mdbx_env_close(env);
+
+  return rc ? EXIT_FAILURE : EXIT_SUCCESS;
+}