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cursor.cpp
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395 lines (367 loc) · 12.7 KB
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#include "lmdb-js.h"
#include <string.h>
using namespace Napi;
const int INCLUDE_VALUES = 0x100;
const int REVERSE = 0x400;
const int VALUES_FOR_KEY = 0x800;
const int ONLY_COUNT = 0x1000;
const int RENEW_CURSOR = 0x2000;
const int EXACT_MATCH = 0x4000;
const int INCLUSIVE_END = 0x8000;
const int EXCLUSIVE_START = 0x10000;
CursorWrap::CursorWrap(const CallbackInfo& info) : Napi::ObjectWrap<CursorWrap>(info) {
this->keyType = LmdbKeyType::StringKey;
this->freeKey = nullptr;
this->endKey.mv_size = 0; // indicates no end key (yet)
if (info.Length() < 1) {
throwError(info.Env(), "Wrong number of arguments");
return;
}
DbiWrap *dw;
napi_unwrap(info.Env(), info[0], (void**)&dw);
int64_t tw_address = 0;
napi_get_value_int64(info.Env(), info[1], &tw_address);
// Open the cursor
MDB_cursor *cursor;
MDB_txn *txn = dw->ew->getReadTxn(tw_address);
int rc = mdb_cursor_open(txn, dw->dbi, &cursor);
if (rc != 0) {
throwLmdbError(info.Env(), rc);
return;
}
info.This().As<Object>().Set("address", Number::New(info.Env(), (size_t) this));
this->cursor = cursor;
this->dw = dw;
this->txn = txn;
this->keyType = keyType;
}
CursorWrap::~CursorWrap() {
if (this->cursor) {
// Don't close cursor here, it is possible that the environment may already be closed, which causes it to crash
//mdb_cursor_close(this->cursor);
}
if (this->freeKey) {
this->freeKey(this->key);
}
}
Value CursorWrap::close(const CallbackInfo& info) {
if (!this->cursor) {
return throwError(info.Env(), "cursor.close: Attempt to close a closed cursor!");
}
mdb_cursor_close(this->cursor);
this->cursor = nullptr;
return info.Env().Undefined();
}
Value CursorWrap::del(const CallbackInfo& info) {
int flags = 0;
if (info.Length() == 1) {
if (!info[0].IsObject()) {
return throwError(info.Env(), "cursor.del: Invalid options argument. It should be an object.");
}
auto options = info[0].As<Object>();
setFlagFromValue(&flags, MDB_NODUPDATA, "noDupData", false, options);
}
int rc = mdb_cursor_del(this->cursor, flags);
if (rc != 0) {
return throwLmdbError(info.Env(), rc);
}
return info.Env().Undefined();
}
int CursorWrap::returnEntry(int lastRC, MDB_val &key, MDB_val &data) {
if (lastRC) {
if (lastRC == MDB_NOTFOUND)
return 0;
else {
return lastRC > 0 ? -lastRC : lastRC;
}
}
if (endKey.mv_size > 0) {
int comparison;
if (flags & VALUES_FOR_KEY)
comparison = mdb_dcmp(txn, dw->dbi, &endKey, &data);
else
comparison = mdb_cmp(txn, dw->dbi, &endKey, &key);
if ((flags & REVERSE) ? comparison >= 0 : (comparison <= 0)) {
if (!((flags & INCLUSIVE_END) && comparison == 0))
return 0;
}
}
char* keyBuffer = dw->ew->keyBuffer;
if (flags & INCLUDE_VALUES) {
int result = getVersionAndUncompress(data, dw);
bool fits = true;
if (result) {
fits = valToBinaryFast(data, dw); // it fit in the global/compression-target buffer
}
if (fits || result == 2 || data.mv_size < SHARED_BUFFER_THRESHOLD) {// if it was decompressed
*((uint32_t*)keyBuffer) = data.mv_size;
*((uint32_t*)(keyBuffer + 4)) = 0; // buffer id of 0
} else {
EnvWrap::toSharedBuffer(dw->ew->env, (uint32_t*) dw->ew->keyBuffer, data);
}
}
if (!(flags & VALUES_FOR_KEY)) {
memcpy(keyBuffer + 32, key.mv_data, key.mv_size);
*(keyBuffer + 32 + key.mv_size) = 0; // make sure it is null terminated for the sake of better ordered-binary performance
}
return key.mv_size;
}
const int START_ADDRESS_POSITION = 4064;
int32_t CursorWrap::doPosition(uint32_t offset, uint32_t keySize, uint64_t endKeyAddress) {
//char* keyBuffer = dw->ew->keyBuffer;
MDB_val key, data;
int rc;
if (dw->ew->env == nullptr) {
return MDB_BAD_TXN;
}
if (flags & RENEW_CURSOR) { // TODO: check the txn_id to determine if we need to renew
rc = mdb_cursor_renew(txn = dw->ew->getReadTxn(), cursor);
if (rc) {
if (rc > 0)
rc = -rc;
return rc;
}
}
if (endKeyAddress) {
uint32_t* keyBuffer = (uint32_t*) endKeyAddress;
endKey.mv_size = *keyBuffer;
endKey.mv_data = (char*)(keyBuffer + 1);
} else
endKey.mv_size = 0;
iteratingOp = (flags & REVERSE) ?
(flags & INCLUDE_VALUES) ?
(flags & VALUES_FOR_KEY) ? MDB_PREV_DUP : MDB_PREV :
MDB_PREV_NODUP :
(flags & INCLUDE_VALUES) ?
(flags & VALUES_FOR_KEY) ? MDB_NEXT_DUP : MDB_NEXT :
MDB_NEXT_NODUP;
key.mv_size = keySize;
key.mv_data = dw->ew->keyBuffer;
if (keySize == 0) {
rc = mdb_cursor_get(cursor, &key, &data, flags & REVERSE ? MDB_LAST : MDB_FIRST);
} else {
if (flags & VALUES_FOR_KEY) { // only values for this key
// take the next part of the key buffer as a pointer to starting data
uint32_t* startValueBuffer = (uint32_t*)(size_t)(*(double*)(dw->ew->keyBuffer + START_ADDRESS_POSITION));
data.mv_size = endKeyAddress ? *((uint32_t*)startValueBuffer) : 0;
data.mv_data = startValueBuffer + 1;
MDB_val startValue;
if (flags & EXCLUSIVE_START)
startValue = data; // save it for comparison
if (flags & REVERSE) {// reverse through values
startValue = data; // save it for comparison
rc = mdb_cursor_get(cursor, &key, &data, data.mv_size ? MDB_GET_BOTH_RANGE : MDB_SET_KEY);
if (rc) {
if (startValue.mv_size) {
// value specified, but not found, so find key and go to last item
rc = mdb_cursor_get(cursor, &key, &data, MDB_SET_KEY);
if (!rc)
rc = mdb_cursor_get(cursor, &key, &data, MDB_LAST_DUP);
} // else just couldn't find the key
} else { // found entry
if (startValue.mv_size == 0) // no value specified, so go to last value
rc = mdb_cursor_get(cursor, &key, &data, MDB_LAST_DUP);
else if (mdb_dcmp(txn, dw->dbi, &startValue, &data)) // the range found the next value *after* the start
rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV_DUP);
}
} else // forward, just do a get by range
rc = mdb_cursor_get(cursor, &key, &data, data.mv_size ?
(flags & EXACT_MATCH) ? MDB_GET_BOTH : MDB_GET_BOTH_RANGE : MDB_SET_KEY);
if (rc == MDB_NOTFOUND)
return 0;
if (flags & ONLY_COUNT && (!endKeyAddress || (flags & EXACT_MATCH))) {
size_t count;
rc = mdb_cursor_count(cursor, &count);
if (rc)
return rc > 0 ? -rc : rc;
return count;
}
if (flags & EXCLUSIVE_START) {
while(!rc) {
if (mdb_dcmp(txn, dw->dbi, &startValue, &data))
break;
rc = mdb_cursor_get(cursor, &key, &data, iteratingOp);
}
}
} else {
MDB_val firstKey;
if (flags & EXCLUSIVE_START)
firstKey = key; // save it for comparison
if (flags & REVERSE) {// reverse
firstKey = key; // save it for comparison
rc = mdb_cursor_get(cursor, &key, &data, MDB_SET_RANGE);
if (rc)
rc = mdb_cursor_get(cursor, &key, &data, MDB_LAST);
else if (mdb_cmp(txn, dw->dbi, &firstKey, &key)) // the range found the next entry *after* the start
rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV);
else if (dw->flags & MDB_DUPSORT)
// we need to go to the last value of this key
rc = mdb_cursor_get(cursor, &key, &data, MDB_LAST_DUP);
} else // forward, just do a get by range
rc = mdb_cursor_get(cursor, &key, &data, (flags & EXACT_MATCH) ? MDB_SET_KEY : MDB_SET_RANGE);
if (flags & EXCLUSIVE_START) {
while(!rc) {
if (mdb_cmp(txn, dw->dbi, &firstKey, &key))
break;
rc = mdb_cursor_get(cursor, &key, &data, iteratingOp);
}
}
}
}
while (offset-- > 0 && !rc) {
rc = mdb_cursor_get(cursor, &key, &data, iteratingOp);
}
if (flags & ONLY_COUNT) {
uint32_t count = 0;
bool useCursorCount = false;
// if we are in a dupsort database, and we are iterating over all entries, we can just count all the values for each key
if (dw->flags & MDB_DUPSORT) {
if (iteratingOp == MDB_PREV) {
iteratingOp = MDB_PREV_NODUP;
useCursorCount = true;
}
if (iteratingOp == MDB_NEXT) {
iteratingOp = MDB_NEXT_NODUP;
useCursorCount = true;
}
}
while (!rc) {
if (endKey.mv_size > 0) {
int comparison;
if (flags & VALUES_FOR_KEY)
comparison = mdb_dcmp(txn, dw->dbi, &endKey, &data);
else
comparison = mdb_cmp(txn, dw->dbi, &endKey, &key);
if ((flags & REVERSE) ? comparison >= 0 : (comparison <=0)) {
if (!((flags & INCLUSIVE_END) && comparison == 0))
return count;
}
}
if (useCursorCount) {
size_t countForKey;
rc = mdb_cursor_count(cursor, &countForKey);
if (rc) {
if (rc > 0)
rc = -rc;
return rc;
}
count += countForKey;
} else
count++;
rc = mdb_cursor_get(cursor, &key, &data, iteratingOp);
}
return count;
}
// TODO: Handle count?
return returnEntry(rc, key, data);
}
NAPI_FUNCTION(position) {
ARGS(5)
GET_INT64_ARG(0);
CursorWrap* cw = (CursorWrap*) i64;
GET_UINT32_ARG(cw->flags, 1);
uint32_t offset;
GET_UINT32_ARG(offset, 2);
uint32_t keySize;
GET_UINT32_ARG(keySize, 3);
napi_get_value_int64(env, args[4], &i64);
int64_t endKeyAddress = i64;
int32_t result = cw->doPosition(offset, keySize, endKeyAddress);
RETURN_INT32(result);
}
int32_t positionFFI(double cwPointer, uint32_t flags, uint32_t offset, uint32_t keySize, uint64_t endKeyAddress) {
CursorWrap* cw = (CursorWrap*) (size_t) cwPointer;
DbiWrap* dw = cw->dw;
dw->getFast = true;
cw->flags = flags;
return cw->doPosition(offset, keySize, endKeyAddress);
}
NAPI_FUNCTION(iterate) {
ARGS(1)
GET_INT64_ARG(0);
CursorWrap* cw = (CursorWrap*) i64;
MDB_val key, data;
int rc;
if (cw->dw->ew->env == nullptr) rc = MDB_BAD_TXN;
else
rc = mdb_cursor_get(cw->cursor, &key, &data, cw->iteratingOp);
RETURN_INT32(cw->returnEntry(rc, key, data));
}
int32_t iterateFFI(double cwPointer) {
CursorWrap* cw = (CursorWrap*) (size_t) cwPointer;
DbiWrap* dw = cw->dw;
dw->getFast = true;
MDB_val key, data;
if (cw->dw->ew->env == nullptr)
return MDB_BAD_TXN;
int rc = mdb_cursor_get(cw->cursor, &key, &data, cw->iteratingOp);
return cw->returnEntry(rc, key, data);
}
NAPI_FUNCTION(getCurrentValue) {
ARGS(1)
GET_INT64_ARG(0);
CursorWrap* cw = (CursorWrap*) i64;
MDB_val key, data;
int rc = mdb_cursor_get(cw->cursor, &key, &data, MDB_GET_CURRENT);
RETURN_INT32(cw->returnEntry(rc, key, data));
}
napi_finalize noopCursor = [](napi_env, void *, void *) {
// Data belongs to LMDB, we shouldn't free it here
};
NAPI_FUNCTION(getCurrentShared) {
ARGS(1)
GET_INT64_ARG(0);
CursorWrap* cw = (CursorWrap*) i64;
MDB_val key, data;
int rc = mdb_cursor_get(cw->cursor, &key, &data, MDB_GET_CURRENT);
if (rc)
RETURN_INT32(cw->returnEntry(rc, key, data));
getVersionAndUncompress(data, cw->dw);
napi_create_external_buffer(env, data.mv_size,
(char*) data.mv_data, noopCursor, nullptr, &returnValue);
return returnValue;
}
NAPI_FUNCTION(renew) {
ARGS(1)
GET_INT64_ARG(0);
CursorWrap* cw = (CursorWrap*) i64;
mdb_cursor_renew(cw->txn = cw->dw->ew->getReadTxn(), cw->cursor);
RETURN_UNDEFINED;
}
void CursorWrap::setupExports(Napi::Env env, Object exports) {
// CursorWrap: Prepare constructor template
Function CursorClass = DefineClass(env, "Cursor", {
// CursorWrap: Add functions to the prototype
CursorWrap::InstanceMethod("close", &CursorWrap::close),
CursorWrap::InstanceMethod("del", &CursorWrap::del),
});
EXPORT_NAPI_FUNCTION("position", position);
EXPORT_NAPI_FUNCTION("iterate", iterate);
EXPORT_NAPI_FUNCTION("getCurrentValue", getCurrentValue);
EXPORT_NAPI_FUNCTION("getCurrentShared", getCurrentShared);
EXPORT_NAPI_FUNCTION("renew", renew);
EXPORT_FUNCTION_ADDRESS("positionPtr", positionFFI);
EXPORT_FUNCTION_ADDRESS("iteratePtr", iterateFFI);
exports.Set("Cursor", CursorClass);
// cursorTpl->InstanceTemplate()->SetInternalFieldCount(1);
}
// This file contains code from the node-lmdb project
// Copyright (c) 2013-2017 Timur Kristóf
// Copyright (c) 2021 Kristopher Tate
// Licensed to you under the terms of the MIT license
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.