db

Documentation

Overview

Document collection.

Collection management (Database is a collection of collections). Collection management functions may not be invoked concurrently.

Query processor for embedded and HTTP API V2.

Index

• func EvalQueryV2(q interface{}, src *Col, result *map[uint64]struct{}) (err error)
• func GetIn(doc interface{}, path []string) (ret []interface{})
• func StrHash(thing interface{}) uint64
• func V2Complement(subExprs interface{}, src *Col, result *map[uint64]struct{}) (err error)
• func V2EvalAllIDs(src *Col, result *map[uint64]struct{}) (err error)
• func V2EvalUnion(exprs []interface{}, src *Col, result *map[uint64]struct{}) (err error)
• func V2IntRange(intFrom interface{}, expr map[string]interface{}, src *Col, ...) (err error)
• func V2Intersect(subExprs interface{}, src *Col, result *map[uint64]struct{}) (err error)
• func V2Lookup(lookupValue interface{}, expr map[string]interface{}, src *Col, ...) (err error)
• func V2PathExistence(hasPath interface{}, expr map[string]interface{}, src *Col, ...) (err error)
• func V2RegexpLookup(lookupRegexp interface{}, expr map[string]interface{}, src *Col, ...) (err error)
• type Col
  • func OpenCol(dir string) (col *Col, err error)
  • func (col *Col) BackupAndSaveConf() error
  • func (col *Col) Close()
  • func (col *Col) Delete(id uint64)
  • func (col *Col) DeleteByUID(uid string)
  • func (col *Col) DeserializeAll(template interface{}, fun func(id uint64) bool)
  • func (col *Col) DurableDelete(id uint64) error
  • func (col *Col) DurableInsert(doc interface{}) (id uint64, err error)
  • func (col *Col) DurableUpdate(id uint64, doc interface{}) (newID uint64, err error)
  • func (col *Col) Flush() error
  • func (col *Col) ForAll(fun func(id uint64, doc interface{}) bool)
  • func (col *Col) Index(path []string) error
  • func (col *Col) IndexDoc(id uint64, doc interface{})
  • func (col *Col) Insert(doc interface{}) (id uint64, err error)
  • func (col *Col) InsertWithUID(doc interface{}) (newID uint64, newUID string, err error)
  • func (col *Col) LoadConf() error
  • func (col *Col) Read(id uint64, doc interface{}) error
  • func (col *Col) ReadByUID(uid string, doc interface{}) (uint64, error)
  • func (col *Col) ReassignUID(id uint64) (newID uint64, newUID string, err error)
  • func (col *Col) Unindex(path []string) error
  • func (col *Col) UnindexDoc(id uint64, doc interface{})
  • func (col *Col) Update(id uint64, doc interface{}) (newID uint64, err error)
  • func (col *Col) UpdateByUID(uid string, doc interface{}) (newID uint64, err error)
• type Config
• type DB
  • func OpenDB(dir string) (db *DB, err error)
  • func (db *DB) Close()
  • func (db *DB) Create(name string) (err error)
  • func (db *DB) Drop(name string) (err error)
  • func (db *DB) Flush()
  • func (db *DB) Rename(oldName, newName string) (err error)
  • func (db *DB) Scrub(name string) (err error)
  • func (db *DB) Use(name string) *Col
• type IndexConf

Functions

func EvalQueryV2

func EvalQueryV2(q interface{}, src *Col, result *map[uint64]struct{}) (err error)

Main entrance to query processor - evaluate a query and put result into result map (as map keys).

func GetIn

func GetIn(doc interface{}, path []string) (ret []interface{})

Resolve the attribute(s) in the document structure along the given path.

func StrHash

func StrHash(thing interface{}) uint64

Return string hash code (algorithm inspired by Java String.hashCode())

func V2Complement

func V2Complement(subExprs interface{}, src *Col, result *map[uint64]struct{}) (err error)

Calculate complement of sub query results.

func V2EvalAllIDs

func V2EvalAllIDs(src *Col, result *map[uint64]struct{}) (err error)

Put all document IDs into result.

func V2EvalUnion

func V2EvalUnion(exprs []interface{}, src *Col, result *map[uint64]struct{}) (err error)

Calculate union of sub-query results.

func V2IntRange

func V2IntRange(intFrom interface{}, expr map[string]interface{}, src *Col, result *map[uint64]struct{}) (err error)

Scan hash table or collection documents using an integer range.

func V2Intersect

func V2Intersect(subExprs interface{}, src *Col, result *map[uint64]struct{}) (err error)

Calculate intersection of sub query results.

func V2Lookup

func V2Lookup(lookupValue interface{}, expr map[string]interface{}, src *Col, result *map[uint64]struct{}) (err error)

Execute value equity check ("attribute == value") using hash lookup or collection scan.

func V2PathExistence

func V2PathExistence(hasPath interface{}, expr map[string]interface{}, src *Col, result *map[uint64]struct{}) (err error)

Execute value existence check.

func V2RegexpLookup

func V2RegexpLookup(lookupRegexp interface{}, expr map[string]interface{}, src *Col, result *map[uint64]struct{}) (err error)

Execute value match regexp using hash lookup or collection scan.

Types

type Col

type Col struct {
	Data                                    *file.ColFile              // Data file
	Config                                  *Config                    // Index configuration
	Dir, ConfigFileName, ConfBackupFileName string                     // Directory and file names
	StrHT                                   map[string]*file.HashTable // Index path to Hash Table mapping
	StrIC                                   map[string]*IndexConf      // Index path to index configuration mapping
}

func OpenCol

func OpenCol(dir string) (col *Col, err error)

Open a collection.

func (*Col) BackupAndSaveConf

func (col *Col) BackupAndSaveConf() error

Copy existing index configuration to backup, then save the latest index configuration.

func (*Col) Close

func (col *Col) Close()

Close the collection.

func (*Col) Delete

func (col *Col) Delete(id uint64)

Delete a document by ID.

func (*Col) DeleteByUID

func (col *Col) DeleteByUID(uid string)

Delete a document by UID.

func (*Col) DeserializeAll

func (col *Col) DeserializeAll(template interface{}, fun func(id uint64) bool)

Deserialize each document into template (pointer to an initialized struct), invoke the function on the deserialized document (Collection Scan).

func (*Col) DurableDelete

func (col *Col) DurableDelete(id uint64) error

Delete a document and immediately flush all buffers.

func (*Col) DurableInsert

func (col *Col) DurableInsert(doc interface{}) (id uint64, err error)

Insert a new document and immediately flush all buffers.

func (*Col) DurableUpdate

func (col *Col) DurableUpdate(id uint64, doc interface{}) (newID uint64, err error)

Update a document and immediately flush all buffers.

func (*Col) Flush

func (col *Col) Flush() error

Flush collection data and index files.

func (*Col) ForAll

func (col *Col) ForAll(fun func(id uint64, doc interface{}) bool)

Deserialize each document and invoke the function on the deserialized docuemnt (Collection Scsn).

func (*Col) Index

func (col *Col) Index(path []string) error

Create a new index. Do not operate on this collection until it finishes!

func (*Col) IndexDoc

func (col *Col) IndexDoc(id uint64, doc interface{})

Put the document on all indexes.

func (*Col) Insert

func (col *Col) Insert(doc interface{}) (id uint64, err error)

Insert a new document.

func (*Col) InsertWithUID

func (col *Col) InsertWithUID(doc interface{}) (newID uint64, newUID string, err error)

Insert a new document, and assign it a UID.

func (*Col) LoadConf

func (col *Col) LoadConf() error

Load index configurations, and open each index file.

func (*Col) Read

func (col *Col) Read(id uint64, doc interface{}) error

Retrieve document by ID.

func (*Col) ReadByUID

func (col *Col) ReadByUID(uid string, doc interface{}) (uint64, error)

Retrieve documentby UID, return its ID.

func (*Col) ReassignUID

func (col *Col) ReassignUID(id uint64) (newID uint64, newUID string, err error)

Give a document (identified by ID) a new UID.

func (*Col) Unindex

func (col *Col) Unindex(path []string) error

Remove an index. Do not operate on this collection until it finishes!

func (*Col) UnindexDoc

func (col *Col) UnindexDoc(id uint64, doc interface{})

Remove the document from all indexes.

func (*Col) Update

func (col *Col) Update(id uint64, doc interface{}) (newID uint64, err error)

Update a document, return its new ID.

func (*Col) UpdateByUID

func (col *Col) UpdateByUID(uid string, doc interface{}) (newID uint64, err error)

Identify a document using UID and update it, return its new ID.

type Config

type Config struct {
	Indexes []IndexConf
}

type DB

type DB struct {
	Dir    string          // Database directory path
	StrCol map[string]*Col // Collection name to collection mapping
}

func OpenDB

func OpenDB(dir string) (db *DB, err error)

Open a database.

func (*DB) Close

func (db *DB) Close()

Close all collections.

func (*DB) Create

func (db *DB) Create(name string) (err error)

Create a collection.

func (*DB) Drop

func (db *DB) Drop(name string) (err error)

Drop (delete) a collection.

func (*DB) Flush

func (db *DB) Flush()

Flush all collection data and index files.

func (*DB) Rename

func (db *DB) Rename(oldName, newName string) (err error)

Rename a collection.

func (*DB) Scrub

func (db *DB) Scrub(name string) (err error)

Repair damaged documents/indexes, collect unused space along the way.

func (*DB) Use

func (db *DB) Use(name string) *Col

Return collection reference by collection name. This function is safe for concurrent use.

type IndexConf

type IndexConf struct {
	FileName            string
	PerBucket, HashBits uint64
	IndexedPath         []string
}