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arangodb/arangod/Ahuacatl/ahuacatl-collections.c

559 lines
17 KiB
C

////////////////////////////////////////////////////////////////////////////////
/// @brief Ahuacatl, collection
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2010-2012 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 triAGENS GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2012, triagens GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#include "Ahuacatl/ahuacatl-collections.h"
#include "Ahuacatl/ahuacatl-access-optimiser.h"
#include "VocBase/index.h"
// -----------------------------------------------------------------------------
// --SECTION-- private functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup Ahuacatl
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief get collection/index id as a string
///
/// The caller must free the result string
////////////////////////////////////////////////////////////////////////////////
static char* GetIndexIdString (TRI_aql_collection_hint_t* const hint) {
TRI_string_buffer_t buffer;
char* result;
TRI_InitStringBuffer(&buffer, TRI_UNKNOWN_MEM_ZONE);
TRI_AppendUInt64StringBuffer(&buffer, hint->_collection->_collection->_cid);
TRI_AppendCharStringBuffer(&buffer, '/');
TRI_AppendUInt64StringBuffer(&buffer, hint->_index->_idx->_iid);
result = TRI_DuplicateStringZ(TRI_UNKNOWN_MEM_ZONE, buffer._buffer);
TRI_DestroyStringBuffer(&buffer);
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief comparator function to sort collections by name
////////////////////////////////////////////////////////////////////////////////
static int CollectionNameComparator (const void* l, const void* r) {
TRI_aql_collection_t* left = *((TRI_aql_collection_t**) l);
TRI_aql_collection_t* right = *((TRI_aql_collection_t**) r);
return strcmp(left->_name, right->_name);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief create a collection container
////////////////////////////////////////////////////////////////////////////////
static TRI_aql_collection_t* CreateCollectionContainer (const char* const name) {
TRI_aql_collection_t* collection;
assert(name);
collection = (TRI_aql_collection_t*) TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, sizeof(TRI_aql_collection_t), false);
if (!collection) {
return NULL;
}
collection->_name = (char*) name;
collection->_collection = NULL;
collection->_barrier = NULL;
collection->_readLocked = false;
return collection;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief set up the collection names vector and order it
////////////////////////////////////////////////////////////////////////////////
bool SetupCollections (TRI_aql_context_t* const context) {
size_t i;
size_t n;
bool result = true;
// each collection used is contained once in the assoc. array
// so we do not have to care about duplicate names here
n = context->_collectionNames._nrAlloc;
for (i = 0; i < n; ++i) {
char* name = context->_collectionNames._table[i];
TRI_aql_collection_t* collection;
if (!name) {
continue;
}
collection = CreateCollectionContainer(name);
if (!collection) {
result = false;
TRI_SetErrorContextAql(context, TRI_ERROR_OUT_OF_MEMORY, NULL);
break;
}
TRI_PushBackVectorPointer(&context->_collections, (void*) collection);
}
if (result && n > 0) {
qsort(context->_collections._buffer,
context->_collections._length,
sizeof(void*),
&CollectionNameComparator);
}
// now collections contains the sorted list of collections
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief open all collections used
////////////////////////////////////////////////////////////////////////////////
bool OpenCollections (TRI_aql_context_t* const context) {
size_t i;
size_t n;
n = context->_collections._length;
for (i = 0; i < n; ++i) {
TRI_aql_collection_t* collection = context->_collections._buffer[i];
assert(collection);
assert(collection->_name);
assert(!collection->_collection);
assert(!collection->_barrier);
assert(!collection->_readLocked);
LOG_TRACE("locking collection '%s'", collection->_name);
collection->_collection = TRI_UseCollectionByNameVocBase(context->_vocbase, collection->_name);
if (collection->_collection == NULL) {
TRI_SetErrorContextAql(context, TRI_ERROR_QUERY_COLLECTION_NOT_FOUND, collection->_name);
return false;
}
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @addtogroup Ahuacatl
/// @{
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// @brief get the JSON representation of a collection hint
////////////////////////////////////////////////////////////////////////////////
TRI_json_t* TRI_GetJsonCollectionHintAql (TRI_aql_collection_hint_t* const hint) {
TRI_json_t* result;
if (hint == NULL) {
return NULL;
}
result = TRI_CreateArrayJson(TRI_UNKNOWN_MEM_ZONE);
if (result == NULL) {
return NULL;
}
if (hint->_index == NULL) {
// full table scan
TRI_Insert3ArrayJson(TRI_UNKNOWN_MEM_ZONE,
result,
"accessType",
TRI_CreateStringCopyJson(TRI_UNKNOWN_MEM_ZONE, "all"));
}
else {
// index usage
TRI_index_t* idx = hint->_index->_idx;
TRI_json_t* indexDescription;
TRI_Insert3ArrayJson(TRI_UNKNOWN_MEM_ZONE,
result,
"accessType",
TRI_CreateStringCopyJson(TRI_UNKNOWN_MEM_ZONE, "index"));
indexDescription = TRI_CreateArrayJson(TRI_UNKNOWN_MEM_ZONE);
if (indexDescription != NULL) {
TRI_string_buffer_t* buffer;
char* idString = GetIndexIdString(hint);
// index id
if (idString != NULL) {
TRI_Insert3ArrayJson(TRI_UNKNOWN_MEM_ZONE,
indexDescription,
"id",
TRI_CreateStringCopyJson(TRI_UNKNOWN_MEM_ZONE, idString));
TRI_FreeString(TRI_UNKNOWN_MEM_ZONE, idString);
}
// index type
TRI_Insert3ArrayJson(TRI_UNKNOWN_MEM_ZONE,
indexDescription,
"type",
TRI_CreateStringCopyJson(TRI_UNKNOWN_MEM_ZONE, TRI_TypeNameIndex(idx)));
// index attributes
buffer = TRI_CreateStringBuffer(TRI_UNKNOWN_MEM_ZONE);
if (buffer != NULL) {
size_t i;
for (i = 0; i < idx->_fields._length; i++) {
if (i > 0) {
TRI_AppendStringStringBuffer(buffer, ", ");
}
TRI_AppendStringStringBuffer(buffer, idx->_fields._buffer[i]);
}
TRI_Insert3ArrayJson(TRI_UNKNOWN_MEM_ZONE,
indexDescription,
"attributes",
TRI_CreateStringCopyJson(TRI_UNKNOWN_MEM_ZONE, buffer->_buffer));
TRI_FreeStringBuffer(TRI_UNKNOWN_MEM_ZONE, buffer);
}
}
TRI_Insert3ArrayJson(TRI_UNKNOWN_MEM_ZONE,
result,
"index",
indexDescription);
}
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief create a collection hint
////////////////////////////////////////////////////////////////////////////////
TRI_aql_collection_hint_t* TRI_CreateCollectionHintAql (void) {
TRI_aql_collection_hint_t* hint;
hint = (TRI_aql_collection_hint_t*) TRI_Allocate(TRI_UNKNOWN_MEM_ZONE, sizeof(TRI_aql_collection_hint_t), false);
if (hint == NULL) {
return NULL;
}
hint->_ranges = NULL;
hint->_index = NULL;
hint->_collection = NULL;
return hint;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief free a collection hint
////////////////////////////////////////////////////////////////////////////////
void TRI_FreeCollectionHintAql (TRI_aql_collection_hint_t* const hint) {
assert(hint);
if (hint->_ranges) {
TRI_FreeAccessesAql(hint->_ranges);
}
if (hint->_index) {
TRI_FreeIndexAql(hint->_index);
}
TRI_Free(TRI_UNKNOWN_MEM_ZONE, hint);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief lookup a collection in the internal vector
////////////////////////////////////////////////////////////////////////////////
TRI_aql_collection_t* TRI_GetCollectionAql (const TRI_aql_context_t* const context,
const char* const collectionName) {
size_t i, n;
assert(context);
n = context->_collections._length;
for (i = 0; i < n; ++i) {
TRI_aql_collection_t* col = (TRI_aql_collection_t*) TRI_AtVectorPointer(&context->_collections, i);
if (TRI_EqualString(col->_name, collectionName)) {
return col;
}
}
return NULL;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief unlock all collections used
////////////////////////////////////////////////////////////////////////////////
void TRI_UnlockCollectionsAql (TRI_aql_context_t* const context) {
size_t i;
// unlock in reverse order
i = context->_collections._length;
while (i--) {
TRI_aql_collection_t* collection = context->_collections._buffer[i];
assert(collection);
assert(collection->_name);
if (collection->_collection == NULL) {
// collection not yet opened
continue;
}
LOG_TRACE("unlocking collection '%s'", collection->_name);
TRI_ReleaseCollectionVocBase(context->_vocbase, collection->_collection);
collection->_collection = NULL;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief lock all collections used
////////////////////////////////////////////////////////////////////////////////
bool TRI_LockCollectionsAql (TRI_aql_context_t* const context) {
if (!SetupCollections(context)) {
return false;
}
if (!OpenCollections(context)) {
TRI_UnlockCollectionsAql(context);
return false;
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief read-locks all collections used in a query
////////////////////////////////////////////////////////////////////////////////
bool TRI_ReadLockCollectionsAql (TRI_aql_context_t* const context) {
size_t i;
size_t n;
bool result = true;
// lock in forward order
n = context->_collections._length;
for (i = 0; i < n; ++i) {
int lockResult;
TRI_aql_collection_t* collection = (TRI_aql_collection_t*) context->_collections._buffer[i];
TRI_primary_collection_t* primaryCollection;
assert(collection);
assert(collection->_name);
assert(collection->_collection);
assert(collection->_collection->_collection);
assert(!collection->_readLocked);
assert(!collection->_barrier);
primaryCollection = (TRI_primary_collection_t*) collection->_collection->_collection;
LOG_TRACE("read-locking collection '%s'", collection->_name);
lockResult = primaryCollection->beginRead(primaryCollection);
if (lockResult != TRI_ERROR_NO_ERROR) {
// couldn't acquire the read lock
LOG_WARNING("couldn't acquire read-lock on collection '%s'", collection->_name);
result = false;
TRI_SetErrorContextAql(context, TRI_ERROR_QUERY_COLLECTION_LOCK_FAILED, collection->_name);
break;
}
else {
collection->_readLocked = true;
LOG_TRACE("read-locked collection '%s'", collection->_name);
}
}
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief read-unlocks all collections used in a query
////////////////////////////////////////////////////////////////////////////////
void TRI_ReadUnlockCollectionsAql (TRI_aql_context_t* const context) {
size_t i;
// unlock in reverse order
i = context->_collections._length;
while (i--) {
TRI_aql_collection_t* collection = (TRI_aql_collection_t*) context->_collections._buffer[i];
TRI_primary_collection_t* primaryCollection;
assert(collection);
assert(collection->_name);
if (!collection->_collection) {
// don't unlock collections we weren't able to lock at all
continue;
}
if (!collection->_readLocked) {
// don't unlock non-read-locked collections
continue;
}
assert(collection->_collection->_collection);
assert(!collection->_barrier);
primaryCollection = (TRI_primary_collection_t*) collection->_collection->_collection;
LOG_TRACE("read-unlocking collection '%s'", collection->_name);
primaryCollection->endRead(primaryCollection);
collection->_readLocked = false;
LOG_TRACE("read-unlocked collection '%s'", collection->_name);
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief adds a gc marker for all collections used in a query
////////////////////////////////////////////////////////////////////////////////
bool TRI_AddBarrierCollectionsAql (TRI_aql_context_t* const context) {
size_t i;
size_t n;
bool result = true;
// iterate in forward order
n = context->_collections._length;
for (i = 0; i < n; ++i) {
TRI_barrier_t* ce;
TRI_aql_collection_t* collection = (TRI_aql_collection_t*) context->_collections._buffer[i];
TRI_primary_collection_t* primaryCollection;
assert(collection);
assert(collection->_name);
assert(collection->_collection);
assert(collection->_readLocked);
assert(collection->_collection->_collection);
assert(!collection->_barrier);
primaryCollection = (TRI_primary_collection_t*) collection->_collection->_collection;
LOG_TRACE("adding barrier for collection '%s'", collection->_name);
ce = TRI_CreateBarrierElement(&primaryCollection->_barrierList);
if (!ce) {
// couldn't create the barrier
result = false;
TRI_SetErrorContextAql(context, TRI_ERROR_OUT_OF_MEMORY, NULL);
break;
}
else {
collection->_barrier = ce;
}
}
return result;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief removes the gc markers for all collections used in a query
////////////////////////////////////////////////////////////////////////////////
void TRI_RemoveBarrierCollectionsAql (TRI_aql_context_t* const context) {
size_t i;
// iterate in reverse order
i = context->_collections._length;
while (i--) {
TRI_aql_collection_t* collection = (TRI_aql_collection_t*) context->_collections._buffer[i];
assert(collection);
assert(collection->_name);
if (!collection->_collection || !collection->_readLocked || !collection->_barrier) {
// don't process collections we weren't able to lock at all
continue;
}
assert(collection->_readLocked);
assert(collection->_barrier);
assert(collection->_collection->_collection);
LOG_TRACE("removing barrier for collection '%s'", collection->_name);
TRI_FreeBarrier(collection->_barrier);
collection->_barrier = NULL;
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief add a collection name to the list of collections used
////////////////////////////////////////////////////////////////////////////////
bool TRI_AddCollectionAql (TRI_aql_context_t* const context, const char* const name) {
assert(context);
assert(name);
// duplicates are not a problem here, we simply ignore them
TRI_InsertKeyAssociativePointer(&context->_collectionNames, name, (void*) name, false);
if (context->_collectionNames._nrUsed > AQL_MAX_COLLECTIONS) {
TRI_SetErrorContextAql(context, TRI_ERROR_QUERY_TOO_MANY_COLLECTIONS, NULL);
return false;
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////
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