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C binding for leveldb, better readseq benchmark for SQLite.

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- Added a C binding for LevelDB.
  May be useful as a stable ABI that can be used by 
  programs that keep leveldb in a shared library, 
  or for JNI API.

- Replaced SQLite's readseq benchmark to a more efficient version. 
  SQLite readseq speeds increased by about a factor of 2x 
  from the previous version. Also updated benchmark page to
  reflect readseq speed up.



git-svn-id: https://leveldb.googlecode.com/svn/trunk@46 62dab493-f737-651d-591e-8d6aee1b9529
This commit is contained in:
gabor@google.com 2011-08-05 20:40:49 +00:00
parent 1bfbe76b4e
commit 021ee9c32b
7 changed files with 1036 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
Makefile
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@ -42,6 +42,7 @@ LDFLAGS=$(PLATFORM_LDFLAGS) $(SNAPPY_LDFLAGS) $(GOOGLE_PERFTOOLS_LDFLAGS)
LIBOBJECTS = \
./db/builder.o \
./db/c.o \
./db/db_impl.o \
./db/db_iter.o \
./db/filename.o \
@ -81,6 +82,7 @@ TESTHARNESS = ./util/testharness.o $(TESTUTIL)
TESTS = \
arena_test \
c_test \
cache_test \
coding_test \
corruption_test \
@ -127,6 +129,9 @@ db_bench_tree_db: doc/bench/db_bench_tree_db.o $(LIBOBJECTS) $(TESTUTIL)
arena_test: util/arena_test.o $(LIBOBJECTS) $(TESTHARNESS)
$(CC) $(LDFLAGS) util/arena_test.o $(LIBOBJECTS) $(TESTHARNESS) -o $@
c_test: db/c_test.o $(LIBOBJECTS) $(TESTHARNESS)
$(CC) $(LDFLAGS) db/c_test.o $(LIBOBJECTS) $(TESTHARNESS) -o $@
cache_test: util/cache_test.o $(LIBOBJECTS) $(TESTHARNESS)
$(CC) $(LDFLAGS) util/cache_test.o $(LIBOBJECTS) $(TESTHARNESS) -o $@
@ -182,8 +187,19 @@ IOSVERSION=$(shell defaults read /Developer/Platforms/iPhoneOS.platform/version
mkdir -p ios-arm/$(dir $@)
$(DEVICEROOT)/usr/bin/$(CC) $(CFLAGS) -isysroot $(DEVICEROOT)/SDKs/iPhoneOS$(IOSVERSION).sdk -arch armv6 -arch armv7 $< -o ios-arm/$@
lipo ios-x86/$@ ios-arm/$@ -create -output $@
.c.o:
mkdir -p ios-x86/$(dir $@)
$(SIMULATORROOT)/usr/bin/$(CC) $(CFLAGS) -isysroot $(SIMULATORROOT)/SDKs/iPhoneSimulator$(IOSVERSION).sdk -arch i686 $< -o ios-x86/$@
mkdir -p ios-arm/$(dir $@)
$(DEVICEROOT)/usr/bin/$(CC) $(CFLAGS) -isysroot $(DEVICEROOT)/SDKs/iPhoneOS$(IOSVERSION).sdk -arch armv6 -arch armv7 $< -o ios-arm/$@
lipo ios-x86/$@ ios-arm/$@ -create -output $@
else
.cc.o:
$(CC) $(CFLAGS) $< -o $@
.c.o:
$(CC) $(CFLAGS) $< -o $@
endif

453
db/c.cc Normal file
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@ -0,0 +1,453 @@
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "leveldb/c.h"
#include <stdlib.h>
#include <unistd.h>
#include "leveldb/cache.h"
#include "leveldb/comparator.h"
#include "leveldb/db.h"
#include "leveldb/env.h"
#include "leveldb/iterator.h"
#include "leveldb/options.h"
#include "leveldb/status.h"
#include "leveldb/write_batch.h"
namespace leveldb {
extern "C" {
struct leveldb_t { DB* rep; };
struct leveldb_iterator_t { Iterator* rep; };
struct leveldb_writebatch_t { WriteBatch rep; };
struct leveldb_snapshot_t { const Snapshot* rep; };
struct leveldb_readoptions_t { ReadOptions rep; };
struct leveldb_writeoptions_t { WriteOptions rep; };
struct leveldb_options_t { Options rep; };
struct leveldb_cache_t { Cache* rep; };
struct leveldb_seqfile_t { SequentialFile* rep; };
struct leveldb_randomfile_t { RandomAccessFile* rep; };
struct leveldb_writablefile_t { WritableFile* rep; };
struct leveldb_logger_t { Logger* rep; };
struct leveldb_filelock_t { FileLock* rep; };
struct leveldb_comparator_t : public Comparator {
void* state_;
void (*destructor_)(void*);
int (*compare_)(
void*,
const char* a, size_t alen,
const char* b, size_t blen);
const char* (*name_)(void*);
virtual ~leveldb_comparator_t() {
(*destructor_)(state_);
}
virtual int Compare(const Slice& a, const Slice& b) const {
return (*compare_)(state_, a.data(), a.size(), b.data(), b.size());
}
virtual const char* Name() const {
return (*name_)(state_);
}
// No-ops since the C binding does not support key shortening methods.
virtual void FindShortestSeparator(std::string*, const Slice&) const { }
virtual void FindShortSuccessor(std::string* key) const { }
};
struct leveldb_env_t {
Env* rep;
bool is_default;
};
static bool SaveError(char** errptr, const Status& s) {
assert(errptr != NULL);
if (s.ok()) {
return false;
} else if (*errptr == NULL) {
*errptr = strdup(s.ToString().c_str());
} else {
// TODO(sanjay): Merge with existing error?
free(*errptr);
*errptr = strdup(s.ToString().c_str());
}
return true;
}
static char* CopyString(const std::string& str) {
char* result = reinterpret_cast<char*>(malloc(sizeof(char) * str.size()));
memcpy(result, str.data(), sizeof(char) * str.size());
return result;
}
leveldb_t* leveldb_open(
const leveldb_options_t* options,
const char* name,
char** errptr) {
DB* db;
if (SaveError(errptr, DB::Open(options->rep, std::string(name), &db))) {
return NULL;
}
leveldb_t* result = new leveldb_t;
result->rep = db;
return result;
}
void leveldb_close(leveldb_t* db) {
delete db->rep;
delete db;
}
void leveldb_put(
leveldb_t* db,
const leveldb_writeoptions_t* options,
const char* key, size_t keylen,
const char* val, size_t vallen,
char** errptr) {
SaveError(errptr,
db->rep->Put(options->rep, Slice(key, keylen), Slice(val, vallen)));
}
void leveldb_delete(
leveldb_t* db,
const leveldb_writeoptions_t* options,
const char* key, size_t keylen,
char** errptr) {
SaveError(errptr, db->rep->Delete(options->rep, Slice(key, keylen)));
}
void leveldb_write(
leveldb_t* db,
const leveldb_writeoptions_t* options,
leveldb_writebatch_t* batch,
char** errptr) {
SaveError(errptr, db->rep->Write(options->rep, &batch->rep));
}
char* leveldb_get(
leveldb_t* db,
const leveldb_readoptions_t* options,
const char* key, size_t keylen,
size_t* vallen,
char** errptr) {
char* result = NULL;
std::string tmp;
Status s = db->rep->Get(options->rep, Slice(key, keylen), &tmp);
if (s.ok()) {
*vallen = tmp.size();
result = CopyString(tmp);
} else {
*vallen = 0;
if (!s.IsNotFound()) {
SaveError(errptr, s);
}
}
return result;
}
leveldb_iterator_t* leveldb_create_iterator(
leveldb_t* db,
const leveldb_readoptions_t* options) {
leveldb_iterator_t* result = new leveldb_iterator_t;
result->rep = db->rep->NewIterator(options->rep);
return result;
}
const leveldb_snapshot_t* leveldb_create_snapshot(
leveldb_t* db) {
leveldb_snapshot_t* result = new leveldb_snapshot_t;
result->rep = db->rep->GetSnapshot();
return result;
}
void leveldb_release_snapshot(
leveldb_t* db,
const leveldb_snapshot_t* snapshot) {
db->rep->ReleaseSnapshot(snapshot->rep);
delete snapshot;
}
const char* leveldb_property_value(
leveldb_t* db,
const char* propname) {
std::string tmp;
if (db->rep->GetProperty(Slice(propname), &tmp)) {
return CopyString(tmp);
} else {
return NULL;
}
}
void leveldb_approximate_sizes(
leveldb_t* db,
int num_ranges,
const char* const* range_start_key, const size_t* range_start_key_len,
const char* const* range_limit_key, const size_t* range_limit_key_len,
uint64_t* sizes) {
Range* ranges = new Range[num_ranges];
for (int i = 0; i < num_ranges; i++) {
ranges[i].start = Slice(range_start_key[i], range_start_key_len[i]);
ranges[i].limit = Slice(range_limit_key[i], range_limit_key_len[i]);
}
db->rep->GetApproximateSizes(ranges, num_ranges, sizes);
delete[] ranges;
}
void leveldb_destroy_db(
const leveldb_options_t* options,
const char* name,
char** errptr) {
SaveError(errptr, DestroyDB(name, options->rep));
}
void leveldb_repair_db(
const leveldb_options_t* options,
const char* name,
char** errptr) {
SaveError(errptr, RepairDB(name, options->rep));
}
void leveldb_iter_destroy(leveldb_iterator_t* iter) {
delete iter->rep;
delete iter;
}
unsigned char leveldb_iter_valid(const leveldb_iterator_t* iter) {
return iter->rep->Valid();
}
void leveldb_iter_seek_to_first(leveldb_iterator_t* iter) {
iter->rep->SeekToFirst();
}
void leveldb_iter_seek_to_last(leveldb_iterator_t* iter) {
iter->rep->SeekToLast();
}
void leveldb_iter_seek(leveldb_iterator_t* iter, const char* k, size_t klen) {
iter->rep->Seek(Slice(k, klen));
}
void leveldb_iter_next(leveldb_iterator_t* iter) {
iter->rep->Next();
}
void leveldb_iter_prev(leveldb_iterator_t* iter) {
iter->rep->Prev();
}
const char* leveldb_iter_key(const leveldb_iterator_t* iter, size_t* klen) {
Slice s = iter->rep->key();
*klen = s.size();
return s.data();
}
const char* leveldb_iter_value(const leveldb_iterator_t* iter, size_t* vlen) {
Slice s = iter->rep->value();
*vlen = s.size();
return s.data();
}
void leveldb_iter_get_error(const leveldb_iterator_t* iter, char** errptr) {
SaveError(errptr, iter->rep->status());
}
leveldb_writebatch_t* leveldb_writebatch_create() {
return new leveldb_writebatch_t;
}
void leveldb_writebatch_destroy(leveldb_writebatch_t* b) {
delete b;
}
void leveldb_writebatch_clear(leveldb_writebatch_t* b) {
b->rep.Clear();
}
void leveldb_writebatch_put(
leveldb_writebatch_t* b,
const char* key, size_t klen,
const char* val, size_t vlen) {
b->rep.Put(Slice(key, klen), Slice(val, vlen));
}
void leveldb_writebatch_delete(
leveldb_writebatch_t* b,
const char* key, size_t klen) {
b->rep.Delete(Slice(key, klen));
}
void leveldb_writebatch_iterate(
leveldb_writebatch_t* b,
void* state,
void (*put)(void*, const char* k, size_t klen, const char* v, size_t vlen),
void (*deleted)(void*, const char* k, size_t klen)) {
class H : public WriteBatch::Handler {
public:
void* state_;
void (*put_)(void*, const char* k, size_t klen, const char* v, size_t vlen);
void (*deleted_)(void*, const char* k, size_t klen);
virtual void Put(const Slice& key, const Slice& value) {
(*put_)(state_, key.data(), key.size(), value.data(), value.size());
}
virtual void Delete(const Slice& key) {
(*deleted_)(state_, key.data(), key.size());
}
};
H handler;
handler.state_ = state;
handler.put_ = put;
handler.deleted_ = deleted;
b->rep.Iterate(&handler);
}
leveldb_options_t* leveldb_options_create() {
return new leveldb_options_t;
}
void leveldb_options_destroy(leveldb_options_t* options) {
delete options;
}
void leveldb_options_set_comparator(
leveldb_options_t* opt,
leveldb_comparator_t* cmp) {
opt->rep.comparator = cmp;
}
void leveldb_options_set_create_if_missing(
leveldb_options_t* opt, unsigned char v) {
opt->rep.create_if_missing = v;
}
void leveldb_options_set_error_if_exists(
leveldb_options_t* opt, unsigned char v) {
opt->rep.error_if_exists = v;
}
void leveldb_options_set_paranoid_checks(
leveldb_options_t* opt, unsigned char v) {
opt->rep.paranoid_checks = v;
}
void leveldb_options_set_env(leveldb_options_t* opt, leveldb_env_t* env) {
opt->rep.env = (env ? env->rep : NULL);
}
void leveldb_options_set_info_log(leveldb_options_t* opt, leveldb_logger_t* l) {
opt->rep.info_log = (l ? l->rep : NULL);
}
void leveldb_options_set_write_buffer_size(leveldb_options_t* opt, size_t s) {
opt->rep.write_buffer_size = s;
}
void leveldb_options_set_max_open_files(leveldb_options_t* opt, int n) {
opt->rep.max_open_files = n;
}
void leveldb_options_set_cache(leveldb_options_t* opt, leveldb_cache_t* c) {
opt->rep.block_cache = c->rep;
}
void leveldb_options_set_block_size(leveldb_options_t* opt, size_t s) {
opt->rep.block_size = s;
}
void leveldb_options_set_block_restart_interval(leveldb_options_t* opt, int n) {
opt->rep.block_restart_interval = n;
}
void leveldb_options_set_compression(leveldb_options_t* opt, int t) {
opt->rep.compression = static_cast<CompressionType>(t);
}
leveldb_comparator_t* leveldb_comparator_create(
void* state,
void (*destructor)(void*),
int (*compare)(
void*,
const char* a, size_t alen,
const char* b, size_t blen),
const char* (*name)(void*)) {
leveldb_comparator_t* result = new leveldb_comparator_t;
result->state_ = state;
result->destructor_ = destructor;
result->compare_ = compare;
result->name_ = name;
return result;
}
void leveldb_comparator_destroy(leveldb_comparator_t* cmp) {
delete cmp;
}
leveldb_readoptions_t* leveldb_readoptions_create() {
return new leveldb_readoptions_t;
}
void leveldb_readoptions_destroy(leveldb_readoptions_t* opt) {
delete opt;
}
void leveldb_readoptions_set_verify_checksums(
leveldb_readoptions_t* opt,
unsigned char v) {
opt->rep.verify_checksums = v;
}
void leveldb_readoptions_set_fill_cache(
leveldb_readoptions_t* opt, unsigned char v) {
opt->rep.fill_cache = v;
}
void leveldb_readoptions_set_snapshot(
leveldb_readoptions_t* opt,
const leveldb_snapshot_t* snap) {
opt->rep.snapshot = (snap ? snap->rep : NULL);
}
leveldb_writeoptions_t* leveldb_writeoptions_create() {
return new leveldb_writeoptions_t;
}
void leveldb_writeoptions_destroy(leveldb_writeoptions_t* opt) {
delete opt;
}
void leveldb_writeoptions_set_sync(
leveldb_writeoptions_t* opt, unsigned char v) {
opt->rep.sync = v;
}
leveldb_cache_t* leveldb_cache_create_lru(size_t capacity) {
leveldb_cache_t* c = new leveldb_cache_t;
c->rep = NewLRUCache(capacity);
return c;
}
void leveldb_cache_destroy(leveldb_cache_t* cache) {
delete cache->rep;
delete cache;
}
leveldb_env_t* leveldb_create_default_env() {
leveldb_env_t* result = new leveldb_env_t;
result->rep = Env::Default();
result->is_default = true;
return result;
}
void leveldb_env_destroy(leveldb_env_t* env) {
if (!env->is_default) delete env->rep;
delete env;
}
} // end extern "C"
}

295
db/c_test.c Normal file
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@ -0,0 +1,295 @@
/* Copyright (c) 2011 The LevelDB Authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file. See the AUTHORS file for names of contributors. */
#include "leveldb/c.h"
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
const char* phase = "";
static char dbname[200];
static void StartPhase(const char* name) {
fprintf(stderr, "=== Test %s\n", name);
phase = name;
}
#define CheckNoError(err) \
if ((err) != NULL) { \
fprintf(stderr, "%s:%d: %s: %s\n", __FILE__, __LINE__, phase, (err)); \
abort(); \
}
#define CheckCondition(cond) \
if (!(cond)) { \
fprintf(stderr, "%s:%d: %s: %s\n", __FILE__, __LINE__, phase, #cond); \
abort(); \
}
static void CheckEqual(const char* expected, const char* v, size_t n) {
if (expected == NULL && v == NULL) {
// ok
} else if (expected != NULL && v != NULL && n == strlen(expected) &&
memcmp(expected, v, n) == 0) {
// ok
return;
} else {
fprintf(stderr, "%s: expected '%s', got '%s'\n",
phase,
(expected ? expected : "(null)"),
(v ? v : "(null"));
abort();
}
}
static void Free(char** ptr) {
if (*ptr) {
free(*ptr);
*ptr = NULL;
}
}
static void CheckGet(
leveldb_t* db,
const leveldb_readoptions_t* options,
const char* key,
const char* expected) {
char* err = NULL;
size_t val_len;
char* val;
val = leveldb_get(db, options, key, strlen(key), &val_len, &err);
CheckNoError(err);
CheckEqual(expected, val, val_len);
Free(&val);
}
static void CheckIter(leveldb_iterator_t* iter,
const char* key, const char* val) {
size_t len;
const char* str;
str = leveldb_iter_key(iter, &len);
CheckEqual(key, str, len);
str = leveldb_iter_value(iter, &len);
CheckEqual(val, str, len);
}
// Callback from leveldb_writebatch_iterate()
static void CheckPut(void* ptr,
const char* k, size_t klen,
const char* v, size_t vlen) {
int* state = (int*) ptr;
CheckCondition(*state < 2);
switch (*state) {
case 0:
CheckEqual("bar", k, klen);
CheckEqual("b", v, vlen);
break;
case 1:
CheckEqual("box", k, klen);
CheckEqual("c", v, vlen);
break;
}
(*state)++;
}
// Callback from leveldb_writebatch_iterate()
static void CheckDel(void* ptr, const char* k, size_t klen) {
int* state = (int*) ptr;
CheckCondition(*state == 2);
CheckEqual("bar", k, klen);
(*state)++;
}
static void CmpDestroy(void* arg) { }
static int CmpCompare(void* arg, const char* a, size_t alen,
const char* b, size_t blen) {
int n = (alen < blen) ? alen : blen;
int r = memcmp(a, b, n);
if (r == 0) {
if (alen < blen) r = -1;
else if (alen > blen) r = +1;
}
return r;
}
static const char* CmpName(void* arg) {
return "foo";
}
int main(int argc, char** argv) {
leveldb_t* db;
leveldb_comparator_t* cmp;
leveldb_cache_t* cache;
leveldb_env_t* env;
leveldb_options_t* options;
leveldb_readoptions_t* roptions;
leveldb_writeoptions_t* woptions;
char* err = NULL;
snprintf(dbname, sizeof(dbname), "/tmp/leveldb_c_test-%d",
((int) geteuid()));
StartPhase("create_objects");
cmp = leveldb_comparator_create(NULL, CmpDestroy, CmpCompare, CmpName);
env = leveldb_create_default_env();
cache = leveldb_cache_create_lru(100000);
options = leveldb_options_create();
leveldb_options_set_comparator(options, cmp);
leveldb_options_set_error_if_exists(options, 1);
leveldb_options_set_cache(options, cache);
leveldb_options_set_env(options, env);
leveldb_options_set_info_log(options, NULL);
leveldb_options_set_write_buffer_size(options, 100000);
leveldb_options_set_paranoid_checks(options, 1);
leveldb_options_set_max_open_files(options, 10);
leveldb_options_set_block_size(options, 1024);
leveldb_options_set_block_restart_interval(options, 8);
leveldb_options_set_compression(options, leveldb_no_compression);
roptions = leveldb_readoptions_create();
leveldb_readoptions_set_verify_checksums(roptions, 1);
leveldb_readoptions_set_fill_cache(roptions, 0);
woptions = leveldb_writeoptions_create();
leveldb_writeoptions_set_sync(woptions, 1);
StartPhase("destroy");
leveldb_destroy_db(options, dbname, &err);
Free(&err);
StartPhase("open_error");
db = leveldb_open(options, dbname, &err);
CheckCondition(err != NULL);
Free(&err);
StartPhase("open");
leveldb_options_set_create_if_missing(options, 1);
db = leveldb_open(options, dbname, &err);
CheckNoError(err);
CheckGet(db, roptions, "foo", NULL);
StartPhase("put");
leveldb_put(db, woptions, "foo", 3, "hello", 5, &err);
CheckNoError(err);
CheckGet(db, roptions, "foo", "hello");
StartPhase("writebatch");
{
leveldb_writebatch_t* wb = leveldb_writebatch_create();
leveldb_writebatch_put(wb, "foo", 3, "a", 1);
leveldb_writebatch_clear(wb);
leveldb_writebatch_put(wb, "bar", 3, "b", 1);
leveldb_writebatch_put(wb, "box", 3, "c", 1);
leveldb_writebatch_delete(wb, "bar", 3);
leveldb_write(db, woptions, wb, &err);
CheckNoError(err);
CheckGet(db, roptions, "foo", "hello");
CheckGet(db, roptions, "bar", NULL);
CheckGet(db, roptions, "box", "c");
int pos = 0;
leveldb_writebatch_iterate(wb, &pos, CheckPut, CheckDel);
CheckCondition(pos == 3);
leveldb_writebatch_destroy(wb);
}
StartPhase("iter");
{
leveldb_iterator_t* iter = leveldb_create_iterator(db, roptions);
CheckCondition(!leveldb_iter_valid(iter));
leveldb_iter_seek_to_first(iter);
CheckCondition(leveldb_iter_valid(iter));
CheckIter(iter, "box", "c");
leveldb_iter_next(iter);
CheckIter(iter, "foo", "hello");
leveldb_iter_prev(iter);
CheckIter(iter, "box", "c");
leveldb_iter_prev(iter);
CheckCondition(!leveldb_iter_valid(iter));
leveldb_iter_seek_to_last(iter);
CheckIter(iter, "foo", "hello");
leveldb_iter_seek(iter, "b", 1);
CheckIter(iter, "box", "c");
leveldb_iter_get_error(iter, &err);
CheckNoError(err);
leveldb_iter_destroy(iter);
}
StartPhase("approximate_sizes");
{
int i;
int n = 20000;
char keybuf[100];
char valbuf[100];
uint64_t sizes[2];
const char* start[2] = { "a", "k00000000000000010000" };
size_t start_len[2] = { 1, 21 };
const char* limit[2] = { "k00000000000000010000", "z" };
size_t limit_len[2] = { 21, 1 };
leveldb_writeoptions_set_sync(woptions, 0);
for (i = 0; i < n; i++) {
snprintf(keybuf, sizeof(keybuf), "k%020d", i);
snprintf(valbuf, sizeof(valbuf), "v%020d", i);
leveldb_put(db, woptions, keybuf, strlen(keybuf), valbuf, strlen(valbuf),
&err);
CheckNoError(err);
}
leveldb_approximate_sizes(db, 2, start, start_len, limit, limit_len, sizes);
CheckCondition(sizes[0] > 0);
CheckCondition(sizes[1] > 0);
}
StartPhase("property");
{
char* prop = leveldb_property_value(db, "nosuchprop");
CheckCondition(prop == NULL);
prop = leveldb_property_value(db, "leveldb.stats");
CheckCondition(prop != NULL);
Free(&prop);
}
StartPhase("snapshot");
{
const leveldb_snapshot_t* snap;
snap = leveldb_create_snapshot(db);
leveldb_delete(db, woptions, "foo", 3, &err);
CheckNoError(err);
leveldb_readoptions_set_snapshot(roptions, snap);
CheckGet(db, roptions, "foo", "hello");
leveldb_readoptions_set_snapshot(roptions, NULL);
CheckGet(db, roptions, "foo", NULL);
leveldb_release_snapshot(db, snap);
}
StartPhase("repair");
{
leveldb_close(db);
leveldb_options_set_create_if_missing(options, 0);
leveldb_options_set_error_if_exists(options, 0);
leveldb_repair_db(options, dbname, &err);
CheckNoError(err);
db = leveldb_open(options, dbname, &err);
CheckNoError(err);
CheckGet(db, roptions, "foo", NULL);
CheckGet(db, roptions, "bar", NULL);
CheckGet(db, roptions, "box", "c");
}
StartPhase("cleanup");
leveldb_close(db);
leveldb_options_destroy(options);
leveldb_readoptions_destroy(roptions);
leveldb_writeoptions_destroy(woptions);
leveldb_cache_destroy(cache);
leveldb_comparator_destroy(cmp);
leveldb_env_destroy(env);
fprintf(stderr, "PASS\n");
return 0;
}

26
doc/bench/db_bench_sqlite3.cc
View File

@ -23,7 +23,6 @@
// fillseq100K -- write N/1000 100K values in sequential order in async mode
// readseq -- read N times sequentially
// readrandom -- read N times in random order
// readseq100K -- read N/1000 100K values in sequential order in async mode
// readrand100K -- read N/1000 100K values in sequential order in async mode
static const char* FLAGS_benchmarks =
"fillseq,"
@ -38,7 +37,7 @@ static const char* FLAGS_benchmarks =
"readseq,"
"fillrand100K,"
"fillseq100K,"
"readseq100K,"
"readseq,"
"readrand100K,"
;
@ -387,7 +386,7 @@ class Benchmark {
Write(write_sync, SEQUENTIAL, FRESH, num_ / 1000, 100 * 1000, 1);
WalCheckpoint(db_);
} else if (name == Slice("readseq")) {
Read(SEQUENTIAL, 1);
ReadSequential();
} else if (name == Slice("readrandom")) {
Read(RANDOM, 1);
} else if (name == Slice("readrand100K")) {
@ -395,11 +394,6 @@ class Benchmark {
reads_ /= 1000;
Read(RANDOM, 1);
reads_ = n;
} else if (name == Slice("readseq100K")) {
int n = reads_;
reads_ /= 1000;
Read(SEQUENTIAL, 1);
reads_ = n;
} else {
known = false;
if (name != Slice()) { // No error message for empty name
@ -640,6 +634,22 @@ class Benchmark {
ErrorCheck(status);
}
void ReadSequential() {
int status;
sqlite3_stmt *pStmt;
std::string read_str = "SELECT * FROM test ORDER BY key";
status = sqlite3_prepare_v2(db_, read_str.c_str(), -1, &pStmt, NULL);
ErrorCheck(status);
for (int i = 0; i < reads_ && SQLITE_ROW == sqlite3_step(pStmt); i++) {
bytes_ += sqlite3_column_bytes(pStmt, 1) + sqlite3_column_bytes(pStmt, 2);
FinishedSingleOp();
}
status = sqlite3_finalize(pStmt);
ErrorCheck(status);
}
};
}

14
doc/benchmark.html
View File

@ -130,8 +130,8 @@ parameters are varied. For the baseline:</p>
<td class="c2">1,010,000 ops/sec</td>
<td class="c3"><div class="bkct" style="width:95px">&nbsp;</div></td>
<tr><td class="c1">SQLite3</td>
<td class="c2">174,000 ops/sec</td>
<td class="c3"><div class="bsql" style="width:15px">&nbsp;</div></td>
<td class="c2">383,000 ops/sec</td>
<td class="c3"><div class="bsql" style="width:33px">&nbsp;</div></td>
</table>
<h3>B. Random Reads</h3>
<table class="bn bnbase">
@ -386,9 +386,9 @@ MB.</p>
<td class="c3"><div class="bkct" style="width:72px">&nbsp;</div></td>
<td class="c4">(1.06x baseline)</td></tr>
<tr><td class="c1">SQLite3</td>
<td class="c2">210,000 ops/sec</td>
<td class="c3"><div class="bsql" style="width:14px">&nbsp;</div></td>
<td class="c4">(1.20x baseline)</td></tr>
<td class="c2">609,000 ops/sec</td>
<td class="c3"><div class="bsql" style="width:41px">&nbsp;</div></td>
<td class="c4">(1.59x baseline)</td></tr>
</table>
<h4>Random Reads</h4>
@ -425,8 +425,8 @@ database.</p>
<td class="c3"><div class="bkct" style="width:88px">&nbsp;</div></td>
<td class="c4">(3.60x baseline)</td></tr>
<tr><td class="c1">SQLite3</td>
<td class="c2">174,000 ops/sec</td>
<td class="c3"><div class="bsql" style="width:13px">&nbsp;</div></td>
<td class="c2">383,000 ops/sec</td>
<td class="c3"><div class="bsql" style="width:27px">&nbsp;</div></td>
<td class="c4">(1.00x baseline)</td></tr>
</table>
<h4>Random Reads</h4>

246
include/leveldb/c.h Normal file
View File

@ -0,0 +1,246 @@
/* Copyright (c) 2011 The LevelDB Authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file. See the AUTHORS file for names of contributors.
C bindings for leveldb. May be useful as a stable ABI that can be
used by programs that keep leveldb in a shared library, or for
a JNI api.
Does not support:
. getters for the option types
. custom comparators that implement key shortening
. capturing post-write-snapshot
. custom iter, db, env, cache implementations using just the C bindings
Some conventions:
(1) We expose just opaque struct pointers and functions to clients.
This allows us to change internal representations without having to
recompile clients.
(2) For simplicity, there is no equivalent to the Slice type. Instead,
the caller has to pass the pointer and length as separate
arguments.
(3) Errors are represented by a null-terminated c string. NULL
means no error. All operations that can raise an error are passed
a "char** errptr" as the last argument. One of the following must
be true on entry:
*errptr == NULL
*errptr points to a malloc()ed null-terminated error message
On success, a leveldb routine leaves *errptr unchanged.
On failure, leveldb frees the old value of *errptr and
set *errptr to a malloc()ed error message.
(4) Bools have the type unsigned char (0 == false; rest == true)
(5) All of the pointer arguments must be non-NULL.
*/
#ifndef STORAGE_LEVELDB_INCLUDE_C_H_
#define STORAGE_LEVELDB_INCLUDE_C_H_
#ifdef __cplusplus
extern "C" {
#endif
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
/* Exported types */
typedef struct leveldb_t leveldb_t;
typedef struct leveldb_cache_t leveldb_cache_t;
typedef struct leveldb_comparator_t leveldb_comparator_t;
typedef struct leveldb_env_t leveldb_env_t;
typedef struct leveldb_filelock_t leveldb_filelock_t;
typedef struct leveldb_iterator_t leveldb_iterator_t;
typedef struct leveldb_logger_t leveldb_logger_t;
typedef struct leveldb_options_t leveldb_options_t;
typedef struct leveldb_randomfile_t leveldb_randomfile_t;
typedef struct leveldb_readoptions_t leveldb_readoptions_t;
typedef struct leveldb_seqfile_t leveldb_seqfile_t;
typedef struct leveldb_snapshot_t leveldb_snapshot_t;
typedef struct leveldb_writablefile_t leveldb_writablefile_t;
typedef struct leveldb_writebatch_t leveldb_writebatch_t;
typedef struct leveldb_writeoptions_t leveldb_writeoptions_t;
/* DB operations */
extern leveldb_t* leveldb_open(
const leveldb_options_t* options,
const char* name,
char** errptr);
extern void leveldb_close(leveldb_t* db);
extern void leveldb_put(
leveldb_t* db,
const leveldb_writeoptions_t* options,
const char* key, size_t keylen,
const char* val, size_t vallen,
char** errptr);
extern void leveldb_delete(
leveldb_t* db,
const leveldb_writeoptions_t* options,
const char* key, size_t keylen,
char** errptr);
extern void leveldb_write(
leveldb_t* db,
const leveldb_writeoptions_t* options,
leveldb_writebatch_t* batch,
char** errptr);
/* Returns NULL if not found. A malloc()ed array otherwise.
Stores the length of the array in *vallen. */
extern char* leveldb_get(
leveldb_t* db,
const leveldb_readoptions_t* options,
const char* key, size_t keylen,
size_t* vallen,
char** errptr);
extern leveldb_iterator_t* leveldb_create_iterator(
leveldb_t* db,
const leveldb_readoptions_t* options);
extern const leveldb_snapshot_t* leveldb_create_snapshot(
leveldb_t* db);
extern void leveldb_release_snapshot(
leveldb_t* db,
const leveldb_snapshot_t* snapshot);
/* Returns NULL if property name is unknown.
Else returns a pointer to a malloc()-ed null-terminated value. */
extern char* leveldb_property_value(
leveldb_t* db,
const char* propname);
extern void leveldb_approximate_sizes(
leveldb_t* db,
int num_ranges,
const char* const* range_start_key, const size_t* range_start_key_len,
const char* const* range_limit_key, const size_t* range_limit_key_len,
uint64_t* sizes);
/* Management operations */
extern void leveldb_destroy_db(
const leveldb_options_t* options,
const char* name,
char** errptr);
extern void leveldb_repair_db(
const leveldb_options_t* options,
const char* name,
char** errptr);
/* Iterator */
extern void leveldb_iter_destroy(leveldb_iterator_t*);
extern unsigned char leveldb_iter_valid(const leveldb_iterator_t*);
extern void leveldb_iter_seek_to_first(leveldb_iterator_t*);
extern void leveldb_iter_seek_to_last(leveldb_iterator_t*);
extern void leveldb_iter_seek(leveldb_iterator_t*, const char* k, size_t klen);
extern void leveldb_iter_next(leveldb_iterator_t*);
extern void leveldb_iter_prev(leveldb_iterator_t*);
extern const char* leveldb_iter_key(const leveldb_iterator_t*, size_t* klen);
extern const char* leveldb_iter_value(const leveldb_iterator_t*, size_t* vlen);
extern void leveldb_iter_get_error(const leveldb_iterator_t*, char** errptr);
/* Write batch */
extern leveldb_writebatch_t* leveldb_writebatch_create();
extern void leveldb_writebatch_destroy(leveldb_writebatch_t*);
extern void leveldb_writebatch_clear(leveldb_writebatch_t*);
extern void leveldb_writebatch_put(
leveldb_writebatch_t*,
const char* key, size_t klen,
const char* val, size_t vlen);
extern void leveldb_writebatch_delete(
leveldb_writebatch_t*,
const char* key, size_t klen);
extern void leveldb_writebatch_iterate(
leveldb_writebatch_t*,
void* state,
void (*put)(void*, const char* k, size_t klen, const char* v, size_t vlen),
void (*deleted)(void*, const char* k, size_t klen));
/* Options */
extern leveldb_options_t* leveldb_options_create();
extern void leveldb_options_destroy(leveldb_options_t*);
extern void leveldb_options_set_comparator(
leveldb_options_t*,
leveldb_comparator_t*);
extern void leveldb_options_set_create_if_missing(
leveldb_options_t*, unsigned char);
extern void leveldb_options_set_error_if_exists(
leveldb_options_t*, unsigned char);
extern void leveldb_options_set_paranoid_checks(
leveldb_options_t*, unsigned char);
extern void leveldb_options_set_env(leveldb_options_t*, leveldb_env_t*);
extern void leveldb_options_set_info_log(leveldb_options_t*, leveldb_logger_t*);
extern void leveldb_options_set_write_buffer_size(leveldb_options_t*, size_t);
extern void leveldb_options_set_max_open_files(leveldb_options_t*, int);
extern void leveldb_options_set_cache(leveldb_options_t*, leveldb_cache_t*);
extern void leveldb_options_set_block_size(leveldb_options_t*, size_t);
extern void leveldb_options_set_block_restart_interval(leveldb_options_t*, int);
enum {
leveldb_no_compression = 0,
leveldb_snappy_compression = 1
};
extern void leveldb_options_set_compression(leveldb_options_t*, int);
/* Comparator */
extern leveldb_comparator_t* leveldb_comparator_create(
void* state,
void (*destructor)(void*),
int (*compare)(
void*,
const char* a, size_t alen,
const char* b, size_t blen),
const char* (*name)(void*));
extern void leveldb_comparator_destroy(leveldb_comparator_t*);
/* Read options */
extern leveldb_readoptions_t* leveldb_readoptions_create();
extern void leveldb_readoptions_destroy(leveldb_readoptions_t*);
extern void leveldb_readoptions_set_verify_checksums(
leveldb_readoptions_t*,
unsigned char);
extern void leveldb_readoptions_set_fill_cache(
leveldb_readoptions_t*, unsigned char);
extern void leveldb_readoptions_set_snapshot(
leveldb_readoptions_t*,
const leveldb_snapshot_t*);
/* Write options */
extern leveldb_writeoptions_t* leveldb_writeoptions_create();
extern void leveldb_writeoptions_destroy(leveldb_writeoptions_t*);
extern void leveldb_writeoptions_set_sync(
leveldb_writeoptions_t*, unsigned char);
/* Cache */
extern leveldb_cache_t* leveldb_cache_create_lru(size_t capacity);
extern void leveldb_cache_destroy(leveldb_cache_t* cache);
/* Env */
extern leveldb_env_t* leveldb_create_default_env();
extern void leveldb_env_destroy(leveldb_env_t*);
#ifdef __cplusplus
} /* end extern "C" */
#endif
#endif /* STORAGE_LEVELDB_INCLUDE_C_H_ */

1
include/leveldb/db.h
View File

@ -33,6 +33,7 @@ struct Range {
Slice start; // Included in the range
Slice limit; // Not included in the range
Range() { }
Range(const Slice& s, const Slice& l) : start(s), limit(l) { }
};