/**
* Copyright (C) 2013 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#include "mongo/db/ops/modifier_bit.h"
#include "mongo/base/error_codes.h"
#include "mongo/bson/mutable/algorithm.h"
#include "mongo/bson/mutable/document.h"
#include "mongo/db/update/field_checker.h"
#include "mongo/db/update/log_builder.h"
#include "mongo/db/update/path_support.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
namespace mb = mutablebson;
namespace str = mongoutils::str;
struct ModifierBit::PreparedState {
PreparedState(mutablebson::Document& doc)
: doc(doc), idxFound(0), elemFound(doc.end()), noOp(false) {}
// Document that is going to be changed.
mutablebson::Document& doc;
// Index in _fieldRef for which an Element exist in the document.
size_t idxFound;
// Element corresponding to _fieldRef[0.._idxFound].
mutablebson::Element elemFound;
// Value to be applied.
SafeNum newValue;
// True if this update is a no-op
bool noOp;
};
ModifierBit::ModifierBit() : ModifierInterface(), _fieldRef(), _posDollar(0), _ops() {}
ModifierBit::~ModifierBit() {}
Status ModifierBit::init(const BSONElement& modExpr, const Options& opts, bool* positional) {
// Perform standard field name and updateable checks.
_fieldRef.parse(modExpr.fieldName());
Status status = fieldchecker::isUpdatable(_fieldRef);
if (!status.isOK()) {
return status;
}
// If a $-positional operator was used, get the index in which it occurred
// and ensure only one occurrence.
size_t foundCount;
bool foundDollar = fieldchecker::isPositional(_fieldRef, &_posDollar, &foundCount);
if (positional)
*positional = foundDollar;
if (foundDollar && foundCount > 1) {
return Status(ErrorCodes::BadValue,
str::stream() << "Too many positional (i.e. '$') elements found in path '"
<< _fieldRef.dottedField()
<< "'");
}
if (modExpr.type() != mongo::Object)
return Status(ErrorCodes::BadValue,
str::stream() << "The $bit modifier is not compatible with a "
<< typeName(modExpr.type())
<< ". You must pass in an embedded document: "
"{$bit: {field: {and/or/xor: #}}");
if (modExpr.embeddedObject().isEmpty()) {
return Status(ErrorCodes::BadValue,
str::stream() << "You must pass in at least one bitwise operation. "
<< "The format is: "
"{$bit: {field: {and/or/xor: #}}");
}
BSONObjIterator opsIterator(modExpr.embeddedObject());
while (opsIterator.more()) {
BSONElement curOp = opsIterator.next();
const StringData payloadFieldName = curOp.fieldName();
SafeNumOp op = NULL;
if (payloadFieldName == "and") {
op = &SafeNum::bitAnd;
} else if (payloadFieldName == "or") {
op = &SafeNum::bitOr;
} else if (payloadFieldName == "xor") {
op = &SafeNum::bitXor;
} else {
return Status(ErrorCodes::BadValue,
str::stream()
<< "The $bit modifier only supports 'and', 'or', and 'xor', not '"
<< payloadFieldName
<< "' which is an unknown operator: {"
<< curOp
<< "}");
}
if ((curOp.type() != mongo::NumberInt) && (curOp.type() != mongo::NumberLong))
return Status(ErrorCodes::BadValue,
str::stream()
<< "The $bit modifier field must be an Integer(32/64 bit); a '"
<< typeName(curOp.type())
<< "' is not supported here: {"
<< curOp
<< "}");
const OpEntry entry = {SafeNum(curOp), op};
_ops.push_back(entry);
}
dassert(!_ops.empty());
return Status::OK();
}
Status ModifierBit::prepare(mutablebson::Element root,
StringData matchedField,
ExecInfo* execInfo) {
_preparedState.reset(new PreparedState(root.getDocument()));
// If we have a $-positional field, it is time to bind it to an actual field part.
if (_posDollar) {
if (matchedField.empty()) {
return Status(ErrorCodes::BadValue,
str::stream() << "The positional operator did not find the match "
"needed from the query. Unexpanded update: "
<< _fieldRef.dottedField());
}
_fieldRef.setPart(_posDollar, matchedField);
}
// Locate the field name in 'root'.
Status status = pathsupport::findLongestPrefix(
_fieldRef, root, &_preparedState->idxFound, &_preparedState->elemFound);
const auto elemFoundIsArray =
_preparedState->elemFound.ok() && _preparedState->elemFound.getType() == BSONType::Array;
// FindLongestPrefix may say the path does not exist at all, which is fine here, or
// that the path was not viable or otherwise wrong, in which case, the mod cannot
// proceed.
if (status.code() == ErrorCodes::NonExistentPath) {
_preparedState->elemFound = root.getDocument().end();
} else if (!status.isOK()) {
return status;
}
// We register interest in the field name. The driver needs this info to sort out if
// there is any conflict among mods.
execInfo->fieldRef[0] = &_fieldRef;
//
// in-place and no-op logic
//
// If the field path is not fully present, then this mod cannot be in place, nor is a
// noOp.
if (!_preparedState->elemFound.ok() || _preparedState->idxFound < (_fieldRef.numParts() - 1)) {
// If no target element exists, the value we will write is the result of applying
// the operation to a zero-initialized integer element.
_preparedState->newValue = apply(SafeNum(static_cast(0)));
if (elemFoundIsArray) {
// Report that an existing array will gain a new element as a result of this mod.
execInfo->indexOfArrayWithNewElement[0] = _preparedState->idxFound;
}
return Status::OK();
}
if (!_preparedState->elemFound.isIntegral()) {
mb::Element idElem = mb::findElementNamed(root.leftChild(), "_id");
return Status(ErrorCodes::BadValue,
str::stream() << "Cannot apply $bit to a value of non-integral type."
<< idElem.toString()
<< " has the field "
<< _preparedState->elemFound.getFieldName()
<< " of non-integer type "
<< typeName(_preparedState->elemFound.getType()));
}
const SafeNum currentValue = _preparedState->elemFound.getValueSafeNum();
// Apply the op over the existing value and the mod value, and capture the result.
_preparedState->newValue = apply(currentValue);
if (!_preparedState->newValue.isValid()) {
// TODO: Include list of ops, if that is easy, at some future point.
return Status(ErrorCodes::BadValue,
str::stream() << "Failed to apply $bit operations to current value: "
<< currentValue.debugString());
}
// If the values are identical (same type, same value), then this is a no-op.
if (_preparedState->newValue.isIdentical(currentValue)) {
_preparedState->noOp = execInfo->noOp = true;
return Status::OK();
}
return Status::OK();
}
Status ModifierBit::apply() const {
dassert(_preparedState->noOp == false);
// If there's no need to create any further field part, the $bit is simply a value
// assignment.
if (_preparedState->elemFound.ok() && _preparedState->idxFound == (_fieldRef.numParts() - 1)) {
return _preparedState->elemFound.setValueSafeNum(_preparedState->newValue);
}
//
// Complete document path logic
//
// Creates the final element that's going to be $set in 'doc'.
mutablebson::Document& doc = _preparedState->doc;
StringData lastPart = _fieldRef.getPart(_fieldRef.numParts() - 1);
mutablebson::Element elemToSet = doc.makeElementSafeNum(lastPart, _preparedState->newValue);
if (!elemToSet.ok()) {
return Status(ErrorCodes::InternalError, "can't create new element");
}
// Now, we can be in two cases here, as far as attaching the element being set goes:
// (a) none of the parts in the element's path exist, or (b) some parts of the path
// exist but not all.
if (!_preparedState->elemFound.ok()) {
_preparedState->elemFound = doc.root();
_preparedState->idxFound = 0;
} else {
_preparedState->idxFound++;
}
// createPathAt() will complete the path and attach 'elemToSet' at the end of it.
return pathsupport::createPathAt(
_fieldRef, _preparedState->idxFound, _preparedState->elemFound, elemToSet)
.getStatus();
}
Status ModifierBit::log(LogBuilder* logBuilder) const {
mutablebson::Element logElement = logBuilder->getDocument().makeElementSafeNum(
_fieldRef.dottedField(), _preparedState->newValue);
if (!logElement.ok()) {
return Status(ErrorCodes::InternalError,
str::stream() << "Could not append entry to $bit oplog entry: "
<< "set '"
<< _fieldRef.dottedField()
<< "' -> "
<< _preparedState->newValue.debugString());
}
return logBuilder->addToSets(logElement);
}
SafeNum ModifierBit::apply(SafeNum value) const {
OpEntries::const_iterator where = _ops.begin();
const OpEntries::const_iterator end = _ops.end();
for (; where != end; ++where)
value = (value.*(where->op))(where->val);
return value;
}
} // namespace mongo