/*

* Copyright © 2016-2025 The LmdbJava Open Source Project

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

package org.lmdbjava;

import static java.io.File.createTempFile;

import static java.lang.System.getProperty;

import static java.lang.Thread.currentThread;

import static java.util.Objects.requireNonNull;

import static jnr.ffi.LibraryLoader.create;

import static jnr.ffi.Runtime.getRuntime;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.nio.file.Files;

import jnr.ffi.Pointer;

import jnr.ffi.Struct;

import jnr.ffi.annotations.Delegate;

import jnr.ffi.annotations.In;

import jnr.ffi.annotations.Out;

import jnr.ffi.byref.IntByReference;

import jnr.ffi.byref.NativeLongByReference;

import jnr.ffi.byref.PointerByReference;

import jnr.ffi.types.size_t;

/**

* JNR-FFI interface to LMDB.

*

* <p>For performance reasons pointers are used rather than structs.

*/

final class Library {

/**

* Java system property name that can be set to the path of an existing directory into which the

* LMDB system library will be extracted from the LmdbJava JAR. If unspecified the LMDB system

* library is extracted to the <code>java.io.tmpdir</code>. Ignored if the LMDB system library is

* not being extracted from the LmdbJava JAR (as would be the case if other system properties

* defined in <code>TargetName</code> have been set).

*/

public static final String LMDB_EXTRACT_DIR_PROP = "lmdbjava.extract.dir";

/** Indicates the directory where the LMDB system library will be extracted. */

static final String EXTRACT_DIR =

getProperty(LMDB_EXTRACT_DIR_PROP, getProperty("java.io.tmpdir"));

static final Lmdb LIB;

static final jnr.ffi.Runtime RUNTIME;

static {

final String libToLoad;

if (TargetName.IS_EXTERNAL) {

libToLoad = TargetName.RESOLVED_FILENAME;

} else {

libToLoad = extract(TargetName.RESOLVED_FILENAME);

}

LIB = create(Lmdb.class).load(libToLoad);

RUNTIME = getRuntime(LIB);

}

private Library() {}

private static String extract(final String name) {

final String suffix = name.substring(name.lastIndexOf('.'));

final File file;

try {

final File dir = new File(EXTRACT_DIR);

if (!dir.exists() || !dir.isDirectory()) {

throw new IllegalStateException("Invalid extraction directory " + dir);

}

file = createTempFile("lmdbjava-native-library-", suffix, dir);

file.deleteOnExit();

final ClassLoader cl = currentThread().getContextClassLoader();

try (InputStream in = cl.getResourceAsStream(name);

OutputStream out = Files.newOutputStream(file.toPath())) {

requireNonNull(in, "Classpath resource not found");

int bytes;

final byte[] buffer = new byte[4_096];

while (-1 != (bytes = in.read(buffer))) {

out.write(buffer, 0, bytes);

}

}

return file.getAbsolutePath();

} catch (final IOException e) {

throw new LmdbException("Failed to extract " + name, e);

}

}

/** Structure to wrap a native <code>MDB_envinfo</code>. Not for external use. */

public static final class MDB_envinfo extends Struct {

public final Pointer f0_me_mapaddr;

public final size_t f1_me_mapsize;

public final size_t f2_me_last_pgno;

public final size_t f3_me_last_txnid;

public final u_int32_t f4_me_maxreaders;

public final u_int32_t f5_me_numreaders;

MDB_envinfo(final jnr.ffi.Runtime runtime) {

super(runtime);

this.f0_me_mapaddr = new Pointer();

this.f1_me_mapsize = new size_t();

this.f2_me_last_pgno = new size_t();

this.f3_me_last_txnid = new size_t();

this.f4_me_maxreaders = new u_int32_t();

this.f5_me_numreaders = new u_int32_t();

}

}

/** Structure to wrap a native <code>MDB_stat</code>. Not for external use. */

public static final class MDB_stat extends Struct {

public final u_int32_t f0_ms_psize;

public final u_int32_t f1_ms_depth;

public final size_t f2_ms_branch_pages;

public final size_t f3_ms_leaf_pages;

public final size_t f4_ms_overflow_pages;

public final size_t f5_ms_entries;

MDB_stat(final jnr.ffi.Runtime runtime) {

super(runtime);

this.f0_ms_psize = new u_int32_t();

this.f1_ms_depth = new u_int32_t();

this.f2_ms_branch_pages = new size_t();

this.f3_ms_leaf_pages = new size_t();

this.f4_ms_overflow_pages = new size_t();

this.f5_ms_entries = new size_t();

}

}

/** Custom comparator callback used by <code>mdb_set_compare</code>. */

public interface ComparatorCallback {

@Delegate

int compare(@In Pointer keyA, @In Pointer keyB);

}

/** JNR API for MDB-defined C functions. Not for external use. */

public interface Lmdb {

void mdb_cursor_close(@In Pointer cursor);

int mdb_cursor_count(@In Pointer cursor, NativeLongByReference countp);

int mdb_cursor_del(@In Pointer cursor, int flags);

int mdb_cursor_get(@In Pointer cursor, Pointer k, @Out Pointer v, int cursorOp);

int mdb_cursor_open(@In Pointer txn, @In Pointer dbi, PointerByReference cursorPtr);

int mdb_cursor_put(@In Pointer cursor, @In Pointer key, @In Pointer data, int flags);

int mdb_cursor_renew(@In Pointer txn, @In Pointer cursor);

void mdb_dbi_close(@In Pointer env, @In Pointer dbi);

int mdb_dbi_flags(@In Pointer txn, @In Pointer dbi, @Out IntByReference flags);

int mdb_dbi_open(@In Pointer txn, @In byte[] name, int flags, @In Pointer dbiPtr);

int mdb_del(@In Pointer txn, @In Pointer dbi, @In Pointer key, @In Pointer data);

int mdb_drop(@In Pointer txn, @In Pointer dbi, int del);

void mdb_env_close(@In Pointer env);

int mdb_env_copy2(@In Pointer env, @In String path, int flags);

int mdb_env_create(PointerByReference envPtr);

int mdb_env_get_fd(@In Pointer env, @In Pointer fd);

int mdb_env_get_flags(@In Pointer env, int flags);

int mdb_env_get_maxkeysize(@In Pointer env);

int mdb_env_get_maxreaders(@In Pointer env, int readers);

int mdb_env_get_path(@In Pointer env, String path);

int mdb_env_info(@In Pointer env, @Out MDB_envinfo info);

int mdb_env_open(@In Pointer env, @In String path, int flags, int mode);

int mdb_env_set_flags(@In Pointer env, int flags, int onoff);

int mdb_env_set_mapsize(@In Pointer env, @size_t long size);

int mdb_env_set_maxdbs(@In Pointer env, int dbs);

int mdb_env_set_maxreaders(@In Pointer env, int readers);

int mdb_env_stat(@In Pointer env, @Out MDB_stat stat);

int mdb_env_sync(@In Pointer env, int f);

int mdb_get(@In Pointer txn, @In Pointer dbi, @In Pointer key, @Out Pointer data);

int mdb_put(@In Pointer txn, @In Pointer dbi, @In Pointer key, @In Pointer data, int flags);

int mdb_reader_check(@In Pointer env, @Out IntByReference dead);

int mdb_set_compare(@In Pointer txn, @In Pointer dbi, ComparatorCallback cb);

int mdb_stat(@In Pointer txn, @In Pointer dbi, @Out MDB_stat stat);

String mdb_strerror(int rc);

void mdb_txn_abort(@In Pointer txn);

int mdb_txn_begin(@In Pointer env, @In Pointer parentTx, int flags, Pointer txPtr);

int mdb_txn_commit(@In Pointer txn);

Pointer mdb_txn_env(@In Pointer txn);

long mdb_txn_id(@In Pointer txn);

int mdb_txn_renew(@In Pointer txn);

void mdb_txn_reset(@In Pointer txn);

int mdb_cmp(@In Pointer txn, @In Pointer dbi, @In Pointer key1, @In Pointer key2);

Pointer mdb_version(IntByReference major, IntByReference minor, IntByReference patch);

}

}