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arangodb/arangod/Aql/Query.cpp

403 lines
12 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief Aql, query context
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2012-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "Aql/Query.h"
#include "Aql/ExecutionBlock.h"
#include "Aql/ExecutionEngine.h"
#include "Aql/ExecutionPlan.h"
#include "Aql/Parser.h"
#include "Aql/V8Executor.h"
#include "Aql/ExecutionEngine.h"
#include "Aql/Optimizer.h"
#include "Basics/JsonHelper.h"
#include "BasicsC/json.h"
#include "BasicsC/tri-strings.h"
#include "Utils/AqlTransaction.h"
#include "Utils/Exception.h"
#include "Utils/V8TransactionContext.h"
#include "VocBase/vocbase.h"
using namespace triagens::aql;
// -----------------------------------------------------------------------------
// --SECTION-- constructors / destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief creates a query
////////////////////////////////////////////////////////////////////////////////
Query::Query (TRI_vocbase_t* vocbase,
char const* queryString,
size_t queryLength,
TRI_json_t* bindParameters)
: _vocbase(vocbase),
_executor(nullptr),
_queryString(queryString),
_queryLength(queryLength),
_queryJson(),
_type(AQL_QUERY_READ),
_bindParameters(bindParameters),
_collections(vocbase),
_strings() {
TRI_ASSERT(_vocbase != nullptr);
_strings.reserve(32);
}
Query::Query (TRI_vocbase_t* vocbase,
triagens::basics::Json queryStruct,
QueryType Type)
: _vocbase(vocbase),
_executor(nullptr),
_queryString(nullptr),
_queryLength(0),
_queryJson(queryStruct),
_type(Type),
_bindParameters(nullptr),
_collections(vocbase),
_strings() {
TRI_ASSERT(_vocbase != nullptr);
_strings.reserve(32);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief destroys a query
////////////////////////////////////////////////////////////////////////////////
Query::~Query () {
if (_executor != nullptr) {
delete _executor;
_executor = nullptr;
}
// free strings
for (auto it = _strings.begin(); it != _strings.end(); ++it) {
TRI_FreeString(TRI_UNKNOWN_MEM_ZONE, const_cast<char*>(*it));
}
}
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief extract a region from the query
////////////////////////////////////////////////////////////////////////////////
std::string Query::extractRegion (int line,
int column) const {
// note: line numbers reported by bison/flex start at 1, columns start at 0
int currentLine = 1;
int currentColumn = 0;
char c;
char const* p = _queryString;
while ((c = *p)) {
if (currentLine > line ||
(currentLine >= line && currentColumn >= column)) {
break;
}
if (c == '\n') {
++p;
++currentLine;
currentColumn = 0;
}
else if (c == '\r') {
++p;
++currentLine;
currentColumn = 0;
// eat a following newline
if (*p == '\n') {
++p;
}
}
else {
++currentColumn;
++p;
}
}
// p is pointing at the position in the query the parse error occurred at
TRI_ASSERT(p >= _queryString);
size_t offset = static_cast<size_t>(p - _queryString);
static int const SNIPPET_LENGTH = 32;
static char const* SNIPPET_SUFFIX = "...";
if (_queryLength < offset + SNIPPET_LENGTH) {
// return a copy of the region
return std::string(_queryString + offset, _queryLength - offset);
}
// copy query part
std::string result(_queryString + offset, SNIPPET_LENGTH);
result.append(SNIPPET_SUFFIX);
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief register an error
////////////////////////////////////////////////////////////////////////////////
void Query::registerError (int code,
char const* details) {
TRI_ASSERT(code != TRI_ERROR_NO_ERROR);
if (details == nullptr) {
THROW_ARANGO_EXCEPTION(code);
}
else {
THROW_ARANGO_EXCEPTION_PARAMS(code, details);
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief execute an AQL query
////////////////////////////////////////////////////////////////////////////////
QueryResult Query::execute () {
try {
ExecutionPlan* plan;
Parser parser(this);
if (_queryString != nullptr) {
parser.parse();
// put in bind parameters
parser.ast()->injectBindParameters(_bindParameters);
// optimize the ast
parser.ast()->optimize();
// std::cout << "AST: " << triagens::basics::JsonHelper::toString(parser.ast()->toJson(TRI_UNKNOWN_MEM_ZONE)) << "\n";
}
// create the transaction object, but do not start it yet
AQL_TRANSACTION_V8 trx(_vocbase, _collections.collections());
if (_queryString != nullptr) {
// we have an AST
int res = trx.begin();
if (res != TRI_ERROR_NO_ERROR) {
return QueryResult(res, TRI_errno_string(res));
}
plan = ExecutionPlan::instanciateFromAst(parser.ast());
if (plan == nullptr) {
// oops
return QueryResult(TRI_ERROR_INTERNAL);
}
}
else {
// we have an execution plan in JSON format
plan = ExecutionPlan::instanciateFromJson(parser.ast(), _queryJson);
if (plan == nullptr) {
// oops
return QueryResult(TRI_ERROR_INTERNAL);
}
// creating the plan may have produced some collections
// we need to add them to the transaction now (otherwise the query will fail)
trx.addCollections(_collections.collections());
int res = trx.begin();
if (res != TRI_ERROR_NO_ERROR) {
return QueryResult(res, TRI_errno_string(res));
}
}
// Run the query optimiser:
triagens::aql::Optimizer opt;
opt.createPlans(plan); // Now plan and all derived plans belong to the
// optimizer
plan = opt.stealBest(); // Now we own the best one again
TRI_ASSERT(plan != nullptr);
triagens::basics::Json json(triagens::basics::Json::List);
try {
auto engine = ExecutionEngine::instanciateFromPlan(&trx, plan);
try {
AqlItemBlock* value;
while (nullptr != (value = engine->getSome(1, ExecutionBlock::DefaultBatchSize))) {
auto doc = value->getDocumentCollection(0);
size_t const n = value->size();
for (size_t i = 0; i < n; ++i) {
AqlValue val = value->getValue(i, 0);
if (! val.isEmpty()) {
json.add(val.toJson(&trx, doc));
}
}
delete value;
}
delete engine;
}
catch (...) {
delete engine;
throw;
}
}
catch (...) {
delete plan;
throw;
}
delete plan;
trx.commit();
QueryResult result(TRI_ERROR_NO_ERROR);
result.json = json.steal();
return result;
}
catch (triagens::arango::Exception const& ex) {
return QueryResult(ex.code(), ex.message());
}
catch (std::bad_alloc const& ex) {
return QueryResult(TRI_ERROR_OUT_OF_MEMORY, TRI_errno_string(TRI_ERROR_OUT_OF_MEMORY));
}
catch (std::exception const& ex) {
return QueryResult(TRI_ERROR_INTERNAL, ex.what());
}
catch (...) {
return QueryResult(TRI_ERROR_INTERNAL, TRI_errno_string(TRI_ERROR_INTERNAL));
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief parse an AQL query
////////////////////////////////////////////////////////////////////////////////
QueryResult Query::parse () {
try {
Parser parser(this);
return parser.parse();
}
catch (triagens::arango::Exception const& ex) {
return QueryResult(ex.code(), ex.message());
}
catch (...) {
return QueryResult(TRI_ERROR_OUT_OF_MEMORY, TRI_errno_string(TRI_ERROR_OUT_OF_MEMORY));
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief explain an AQL query - TODO: implement and determine return type
////////////////////////////////////////////////////////////////////////////////
void Query::explain () {
}
////////////////////////////////////////////////////////////////////////////////
/// @brief get v8 executor
////////////////////////////////////////////////////////////////////////////////
V8Executor* Query::executor () {
if (_executor == nullptr) {
// the executor is a singleton per query
_executor = new V8Executor;
}
TRI_ASSERT(_executor != nullptr);
return _executor;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief register a string
/// the string is freed when the query is destroyed
////////////////////////////////////////////////////////////////////////////////
char* Query::registerString (char const* p,
size_t length,
bool mustUnescape) {
if (p == nullptr) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
}
if (length == 0) {
static char const* empty = "";
// optimisation for the empty string
return const_cast<char*>(empty);
}
char* copy = nullptr;
if (mustUnescape) {
size_t outLength;
copy = TRI_UnescapeUtf8StringZ(TRI_UNKNOWN_MEM_ZONE, p, length, &outLength);
}
else {
copy = TRI_DuplicateString2Z(TRI_UNKNOWN_MEM_ZONE, p, length);
}
if (copy == nullptr) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
}
try {
_strings.push_back(copy);
}
catch (...) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
}
return copy;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief register a string
/// the string is freed when the query is destroyed
////////////////////////////////////////////////////////////////////////////////
char* Query::registerString (std::string const& p,
bool mustUnescape) {
return registerString(p.c_str(), p.length(), mustUnescape);
}
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End: