diff options
Diffstat (limited to 'src/mongo/s/chunk_diff.h')
| -rw-r--r-- | src/mongo/s/chunk_diff.h | 164 |
1 files changed, 84 insertions, 80 deletions
diff --git a/src/mongo/s/chunk_diff.h b/src/mongo/s/chunk_diff.h index 9a67583a53b..00d713addd5 100644 --- a/src/mongo/s/chunk_diff.h +++ b/src/mongo/s/chunk_diff.h @@ -35,104 +35,108 @@ namespace mongo { - class ChunkType; - struct ChunkVersion; - class CatalogManager; - class Query; +class ChunkType; +struct ChunkVersion; +class CatalogManager; +class Query; - /** - * This class manages and applies diffs from partial config server data reloads. Because the - * config data can be large, we want to update it in small parts, not all-at-once. Once a - * ConfigDiffTracker is created, the current config data is *attached* to it, and it is then - * able to modify the data. - * - * The current form is templated b/c the overall algorithm is identical between mongos and - * mongod, but the actual chunk maps used differ in implementation. We don't want to copy the - * implementation, because the logic is identical, or the chunk data, because that would be - * slow for big clusters, so this is the alternative for now. - * - * TODO: Standardize between mongos and mongod and convert template parameters to types. - */ - template <class ValType, class ShardType> - class ConfigDiffTracker { - public: - // Stores ranges indexed by max or min key - typedef typename std::map<BSONObj, ValType, BSONObjCmp> RangeMap; +/** + * This class manages and applies diffs from partial config server data reloads. Because the + * config data can be large, we want to update it in small parts, not all-at-once. Once a + * ConfigDiffTracker is created, the current config data is *attached* to it, and it is then + * able to modify the data. + * + * The current form is templated b/c the overall algorithm is identical between mongos and + * mongod, but the actual chunk maps used differ in implementation. We don't want to copy the + * implementation, because the logic is identical, or the chunk data, because that would be + * slow for big clusters, so this is the alternative for now. + * + * TODO: Standardize between mongos and mongod and convert template parameters to types. + */ +template <class ValType, class ShardType> +class ConfigDiffTracker { +public: + // Stores ranges indexed by max or min key + typedef typename std::map<BSONObj, ValType, BSONObjCmp> RangeMap; - // Pair of iterators defining a subset of ranges - typedef typename std::pair<typename RangeMap::iterator, - typename RangeMap::iterator> RangeOverlap; + // Pair of iterators defining a subset of ranges + typedef + typename std::pair<typename RangeMap::iterator, typename RangeMap::iterator> RangeOverlap; - // Map of shard identifiers to the maximum chunk version on that shard - typedef typename std::map<ShardType, ChunkVersion> MaxChunkVersionMap; + // Map of shard identifiers to the maximum chunk version on that shard + typedef typename std::map<ShardType, ChunkVersion> MaxChunkVersionMap; - ConfigDiffTracker(); - virtual ~ConfigDiffTracker(); + ConfigDiffTracker(); + virtual ~ConfigDiffTracker(); - /** - * The tracker attaches to a set of ranges with versions, and uses a config server - * connection to update these. Because the set of ranges and versions may be large, they - * aren't owned by the tracker, they're just passed in and updated. Therefore they must all - * stay in scope while the tracker is working. - * - * TODO: Make a standard VersionedRange to encapsulate this info in both mongod and mongos? - */ - void attach(const std::string& ns, - RangeMap& currMap, - ChunkVersion& maxVersion, - MaxChunkVersionMap& maxShardVersions); + /** + * The tracker attaches to a set of ranges with versions, and uses a config server + * connection to update these. Because the set of ranges and versions may be large, they + * aren't owned by the tracker, they're just passed in and updated. Therefore they must all + * stay in scope while the tracker is working. + * + * TODO: Make a standard VersionedRange to encapsulate this info in both mongod and mongos? + */ + void attach(const std::string& ns, + RangeMap& currMap, + ChunkVersion& maxVersion, + MaxChunkVersionMap& maxShardVersions); - // Call after load for more information - int numValidDiffs() const { return _validDiffs; } + // Call after load for more information + int numValidDiffs() const { + return _validDiffs; + } - // Whether or not a range exists in the min/max region - bool isOverlapping(const BSONObj& min, const BSONObj& max); + // Whether or not a range exists in the min/max region + bool isOverlapping(const BSONObj& min, const BSONObj& max); - // Removes all ranges in the region from min/max - void removeOverlapping(const BSONObj& min, const BSONObj& max); + // Removes all ranges in the region from min/max + void removeOverlapping(const BSONObj& min, const BSONObj& max); - // Returns a subset of ranges overlapping the region min/max - RangeOverlap overlappingRange(const BSONObj& min, const BSONObj& max); + // Returns a subset of ranges overlapping the region min/max + RangeOverlap overlappingRange(const BSONObj& min, const BSONObj& max); - // Finds and applies the changes to a collection from the config servers via - // the catalog manager. - // Also includes minor version changes for particular major-version chunks if explicitly - // specified. - // Returns the number of diffs processed, or -1 if the diffs were inconsistent - // Throws a DBException on connection errors - int calculateConfigDiff(CatalogManager* catalogManager); + // Finds and applies the changes to a collection from the config servers via + // the catalog manager. + // Also includes minor version changes for particular major-version chunks if explicitly + // specified. + // Returns the number of diffs processed, or -1 if the diffs were inconsistent + // Throws a DBException on connection errors + int calculateConfigDiff(CatalogManager* catalogManager); - // Applies changes to the config data from a vector of chunks passed in - // Returns the number of diffs processed, or -1 if the diffs were inconsistent - // Throws a DBException on connection errors - int calculateConfigDiff(const std::vector<ChunkType>& chunks); + // Applies changes to the config data from a vector of chunks passed in + // Returns the number of diffs processed, or -1 if the diffs were inconsistent + // Throws a DBException on connection errors + int calculateConfigDiff(const std::vector<ChunkType>& chunks); - // Returns the query needed to find new changes to a collection from the config server - // Needed only if a custom connection is required to the config server - Query configDiffQuery() const; + // Returns the query needed to find new changes to a collection from the config server + // Needed only if a custom connection is required to the config server + Query configDiffQuery() const; - protected: - // Determines which chunks are actually being remembered by our RangeMap - virtual bool isTracked(const ChunkType& chunk) const = 0; +protected: + // Determines which chunks are actually being remembered by our RangeMap + virtual bool isTracked(const ChunkType& chunk) const = 0; - // Whether or not our RangeMap uses min or max keys - virtual bool isMinKeyIndexed() const { return true; } + // Whether or not our RangeMap uses min or max keys + virtual bool isMinKeyIndexed() const { + return true; + } - virtual std::pair<BSONObj, ValType> rangeFor(const ChunkType& chunk) const = 0; + virtual std::pair<BSONObj, ValType> rangeFor(const ChunkType& chunk) const = 0; - virtual ShardType shardFor(const std::string& name) const = 0; + virtual ShardType shardFor(const std::string& name) const = 0; - private: - void _assertAttached() const; +private: + void _assertAttached() const; - std::string _ns; - RangeMap* _currMap; - ChunkVersion* _maxVersion; - MaxChunkVersionMap* _maxShardVersions; + std::string _ns; + RangeMap* _currMap; + ChunkVersion* _maxVersion; + MaxChunkVersionMap* _maxShardVersions; - // Store for later use - int _validDiffs; - }; + // Store for later use + int _validDiffs; +}; -} // namespace mongo +} // namespace mongo |