From 57376f090503d7ef5bc38f138e58e64bdea284a3 Mon Sep 17 00:00:00 2001 From: Ben Johnson Date: Sat, 8 Mar 2014 17:01:49 -0700 Subject: [PATCH] Rename Transaction to Tx. I changed the Transaction/RWTransaction types to Tx/RWTx, respectively. This makes the naming more consistent with other packages such as database/sql. The txnid is changed to txid as well. --- TODO | 13 ----- bucket.go | 22 ++++---- bucket_test.go | 22 ++++---- cursor.go | 20 ++++---- db.go | 114 +++++++++++++++++++++--------------------- db_test.go | 22 ++++---- doc.go | 17 +++---- example_test.go | 18 +++---- freelist.go | 12 ++--- freelist_test.go | 12 ++--- functional_test.go | 6 +-- meta.go | 6 +-- node.go | 40 +++++++-------- rwtransaction.go | 50 +++++++++--------- rwtransaction_test.go | 40 +++++++-------- transaction.go | 64 ++++++++++++------------ transaction_test.go | 54 ++++++++++---------- 17 files changed, 259 insertions(+), 273 deletions(-) delete mode 100644 TODO diff --git a/TODO b/TODO deleted file mode 100644 index 9c8a1a0..0000000 --- a/TODO +++ /dev/null @@ -1,13 +0,0 @@ -TODO -==== -X Open DB. -X Initialize transaction. -- Cursor First, Get(key), Next -- RWTransaction.insert() - - rebalance - - adjust cursors -- RWTransaction Commmit - - - - diff --git a/bucket.go b/bucket.go index 6c1eb5c..e406a6e 100644 --- a/bucket.go +++ b/bucket.go @@ -7,9 +7,9 @@ import ( // Bucket represents a collection of key/value pairs inside the database. type Bucket struct { *bucket - name string - transaction *Transaction - rwtransaction *RWTransaction + name string + tx *Tx + rwtx *RWTx } // bucket represents the on-file representation of a bucket. @@ -25,17 +25,17 @@ func (b *Bucket) Name() string { // Writable returns whether the bucket is writable. func (b *Bucket) Writable() bool { - return (b.rwtransaction != nil) + return (b.rwtx != nil) } // Cursor creates a cursor associated with the bucket. -// The cursor is only valid as long as the Transaction is open. +// The cursor is only valid as long as the transaction is open. // Do not use a cursor after the transaction is closed. func (b *Bucket) Cursor() *Cursor { return &Cursor{ - transaction: b.transaction, - root: b.root, - stack: make([]elemRef, 0), + tx: b.tx, + root: b.root, + stack: make([]elemRef, 0), } } @@ -74,7 +74,7 @@ func (b *Bucket) Put(key []byte, value []byte) error { c.Seek(key) // Insert the key/value. - c.node(b.rwtransaction).put(key, key, value, 0) + c.node(b.rwtx).put(key, key, value, 0) return nil } @@ -92,7 +92,7 @@ func (b *Bucket) Delete(key []byte) error { c.Seek(key) // Delete the node if we have a matching key. - c.node(b.rwtransaction).del(key) + c.node(b.rwtx).del(key) return nil } @@ -130,7 +130,7 @@ func (b *Bucket) ForEach(fn func(k, v []byte) error) error { // Stat returns stats on a bucket. func (b *Bucket) Stat() *BucketStat { s := &BucketStat{} - b.transaction.forEachPage(b.root, 0, func(p *page, depth int) { + b.tx.forEachPage(b.root, 0, func(p *page, depth int) { if (p.flags & leafPageFlag) != 0 { s.LeafPageCount++ s.KeyCount += int(p.count) diff --git a/bucket_test.go b/bucket_test.go index e4ccabd..a599557 100644 --- a/bucket_test.go +++ b/bucket_test.go @@ -27,7 +27,7 @@ func TestBucketGetNonExistent(t *testing.T) { func TestBucketGetFromNode(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") - db.Do(func(txn *RWTransaction) error { + db.Do(func(txn *RWTx) error { b := txn.Bucket("widgets") b.Put([]byte("foo"), []byte("bar")) value := b.Get([]byte("foo")) @@ -54,7 +54,7 @@ func TestBucketPut(t *testing.T) { func TestBucketPutReadOnly(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") - db.With(func(txn *Transaction) error { + db.With(func(txn *Tx) error { b := txn.Bucket("widgets") err := b.Put([]byte("foo"), []byte("bar")) assert.Equal(t, err, ErrBucketNotWritable) @@ -81,7 +81,7 @@ func TestBucketDelete(t *testing.T) { func TestBucketDeleteReadOnly(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") - db.With(func(txn *Transaction) error { + db.With(func(txn *Tx) error { b := txn.Bucket("widgets") err := b.Delete([]byte("foo")) assert.Equal(t, err, ErrBucketNotWritable) @@ -120,7 +120,7 @@ func TestBucketNextSequence(t *testing.T) { func TestBucketNextSequenceReadOnly(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") - db.With(func(txn *Transaction) error { + db.With(func(txn *Tx) error { b := txn.Bucket("widgets") i, err := b.NextSequence() assert.Equal(t, i, 0) @@ -134,7 +134,7 @@ func TestBucketNextSequenceReadOnly(t *testing.T) { func TestBucketNextSequenceOverflow(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") - db.Do(func(txn *RWTransaction) error { + db.Do(func(txn *RWTx) error { b := txn.Bucket("widgets") b.bucket.sequence = uint64(maxInt) seq, err := b.NextSequence() @@ -218,7 +218,7 @@ func TestBucketPutKeyTooLarge(t *testing.T) { // Ensure a bucket can calculate stats. func TestBucketStat(t *testing.T) { withOpenDB(func(db *DB, path string) { - db.Do(func(txn *RWTransaction) error { + db.Do(func(txn *RWTx) error { // Add bucket with lots of keys. txn.CreateBucket("widgets") b := txn.Bucket("widgets") @@ -241,7 +241,7 @@ func TestBucketStat(t *testing.T) { return nil }) - db.With(func(txn *Transaction) error { + db.With(func(txn *Tx) error { b := txn.Bucket("widgets") stat := b.Stat() assert.Equal(t, stat.BranchPageCount, 15) @@ -317,7 +317,7 @@ func TestBucketPutMultiple(t *testing.T) { withOpenDB(func(db *DB, path string) { // Bulk insert all values. db.CreateBucket("widgets") - rwtxn, _ := db.RWTransaction() + rwtxn, _ := db.RWTx() b := rwtxn.Bucket("widgets") for _, item := range items { assert.NoError(t, b.Put(item.Key, item.Value)) @@ -325,7 +325,7 @@ func TestBucketPutMultiple(t *testing.T) { assert.NoError(t, rwtxn.Commit()) // Verify all items exist. - txn, _ := db.Transaction() + txn, _ := db.Tx() b = txn.Bucket("widgets") for _, item := range items { value := b.Get(item.Key) @@ -351,7 +351,7 @@ func TestBucketDeleteQuick(t *testing.T) { withOpenDB(func(db *DB, path string) { // Bulk insert all values. db.CreateBucket("widgets") - rwtxn, _ := db.RWTransaction() + rwtxn, _ := db.RWTx() b := rwtxn.Bucket("widgets") for _, item := range items { assert.NoError(t, b.Put(item.Key, item.Value)) @@ -363,7 +363,7 @@ func TestBucketDeleteQuick(t *testing.T) { assert.NoError(t, db.Delete("widgets", item.Key)) // Anything before our deletion index should be nil. - txn, _ := db.Transaction() + txn, _ := db.Tx() b := txn.Bucket("widgets") for j, exp := range items { if j > i { diff --git a/cursor.go b/cursor.go index f8e28ea..2907b84 100644 --- a/cursor.go +++ b/cursor.go @@ -6,18 +6,18 @@ import ( ) // Cursor represents an iterator that can traverse over all key/value pairs in a bucket in sorted order. -// Cursors can be obtained from a Transaction and are valid as long as the Transaction is open. +// Cursors can be obtained from a transaction and are valid as long as the transaction is open. type Cursor struct { - transaction *Transaction - root pgid - stack []elemRef + tx *Tx + root pgid + stack []elemRef } // First moves the cursor to the first item in the bucket and returns its key and value. // If the bucket is empty then a nil key and value are returned. func (c *Cursor) First() (key []byte, value []byte) { c.stack = c.stack[:0] - p, n := c.transaction.pageNode(c.root) + p, n := c.tx.pageNode(c.root) c.stack = append(c.stack, elemRef{page: p, node: n, index: 0}) c.first() return c.keyValue() @@ -27,7 +27,7 @@ func (c *Cursor) First() (key []byte, value []byte) { // If the bucket is empty then a nil key and value are returned. func (c *Cursor) Last() (key []byte, value []byte) { c.stack = c.stack[:0] - p, n := c.transaction.pageNode(c.root) + p, n := c.tx.pageNode(c.root) ref := elemRef{page: p, node: n} ref.index = ref.count() - 1 c.stack = append(c.stack, ref) @@ -116,7 +116,7 @@ func (c *Cursor) first() { } else { pgid = ref.page.branchPageElement(uint16(ref.index)).pgid } - p, n := c.transaction.pageNode(pgid) + p, n := c.tx.pageNode(pgid) c.stack = append(c.stack, elemRef{page: p, node: n, index: 0}) } } @@ -137,7 +137,7 @@ func (c *Cursor) last() { } else { pgid = ref.page.branchPageElement(uint16(ref.index)).pgid } - p, n := c.transaction.pageNode(pgid) + p, n := c.tx.pageNode(pgid) var nextRef = elemRef{page: p, node: n} nextRef.index = nextRef.count() - 1 @@ -147,7 +147,7 @@ func (c *Cursor) last() { // search recursively performs a binary search against a given page/node until it finds a given key. func (c *Cursor) search(key []byte, pgid pgid) { - p, n := c.transaction.pageNode(pgid) + p, n := c.tx.pageNode(pgid) if p != nil { _assert((p.flags&(branchPageFlag|leafPageFlag)) != 0, "invalid page type: "+p.typ()) } @@ -251,7 +251,7 @@ func (c *Cursor) keyValue() ([]byte, []byte) { } // node returns the node that the cursor is currently positioned on. -func (c *Cursor) node(t *RWTransaction) *node { +func (c *Cursor) node(t *RWTx) *node { _assert(len(c.stack) > 0, "accessing a node with a zero-length cursor stack") // If the top of the stack is a leaf node then just return it. diff --git a/db.go b/db.go index 30b5c47..bf7be45 100644 --- a/db.go +++ b/db.go @@ -19,19 +19,19 @@ const maxMmapStep = 1 << 30 // 1GB // All data access is performed through transactions which can be obtained through the DB. // All the functions on DB will return a ErrDatabaseNotOpen if accessed before Open() is called. type DB struct { - os _os - syscall _syscall - path string - file file - metafile file - data []byte - meta0 *meta - meta1 *meta - pageSize int - opened bool - rwtransaction *RWTransaction - transactions []*Transaction - freelist *freelist + os _os + syscall _syscall + path string + file file + metafile file + data []byte + meta0 *meta + meta1 *meta + pageSize int + opened bool + rwtx *RWTx + txs []*Tx + freelist *freelist rwlock sync.Mutex // Allows only one writer at a time. metalock sync.Mutex // Protects meta page access. @@ -112,7 +112,7 @@ func (db *DB) Open(path string, mode os.FileMode) error { } // Read in the freelist. - db.freelist = &freelist{pending: make(map[txnid][]pgid)} + db.freelist = &freelist{pending: make(map[txid][]pgid)} db.freelist.read(db.page(db.meta().freelist)) // Mark the database as opened and return. @@ -127,8 +127,8 @@ func (db *DB) mmap(minsz int) error { defer db.mmaplock.Unlock() // Dereference all mmap references before unmapping. - if db.rwtransaction != nil { - db.rwtransaction.dereference() + if db.rwtx != nil { + db.rwtx.dereference() } // Unmap existing data before continuing. @@ -218,7 +218,7 @@ func (db *DB) init() error { m.freelist = 2 m.buckets = 3 m.pgid = 4 - m.txnid = txnid(i) + m.txid = txid(i) } // Write an empty freelist at page 3. @@ -259,11 +259,11 @@ func (db *DB) close() { db.munmap() } -// Transaction creates a read-only transaction. +// Tx creates a read-only transaction. // Multiple read-only transactions can be used concurrently. // // IMPORTANT: You must close the transaction after you are finished or else the database will not reclaim old pages. -func (db *DB) Transaction() (*Transaction, error) { +func (db *DB) Tx() (*Tx, error) { db.metalock.Lock() defer db.metalock.Unlock() @@ -278,23 +278,23 @@ func (db *DB) Transaction() (*Transaction, error) { } // Create a transaction associated with the database. - t := &Transaction{} + t := &Tx{} t.init(db) // Keep track of transaction until it closes. - db.transactions = append(db.transactions, t) + db.txs = append(db.txs, t) return t, nil } -// RWTransaction creates a read/write transaction. +// RWTx creates a read/write transaction. // Only one read/write transaction is allowed at a time. // You must call Commit() or Rollback() on the transaction to close it. -func (db *DB) RWTransaction() (*RWTransaction, error) { +func (db *DB) RWTx() (*RWTx, error) { db.metalock.Lock() defer db.metalock.Unlock() - // Obtain writer lock. This is released by the RWTransaction when it closes. + // Obtain writer lock. This is released by the RWTx when it closes. db.rwlock.Lock() // Exit if the database is not open yet. @@ -304,13 +304,13 @@ func (db *DB) RWTransaction() (*RWTransaction, error) { } // Create a transaction associated with the database. - t := &RWTransaction{} + t := &RWTx{} t.init(db) - db.rwtransaction = t + db.rwtx = t // Free any pages associated with closed read-only transactions. - var minid txnid = 0xFFFFFFFFFFFFFFFF - for _, t := range db.transactions { + var minid txid = 0xFFFFFFFFFFFFFFFF + for _, t := range db.txs { if t.id() < minid { minid = t.id() } @@ -322,8 +322,8 @@ func (db *DB) RWTransaction() (*RWTransaction, error) { return t, nil } -// removeTransaction removes a transaction from the database. -func (db *DB) removeTransaction(t *Transaction) { +// removeTx removes a transaction from the database. +func (db *DB) removeTx(t *Tx) { db.metalock.Lock() defer db.metalock.Unlock() @@ -331,21 +331,21 @@ func (db *DB) removeTransaction(t *Transaction) { db.mmaplock.RUnlock() // Remove the transaction. - for i, txn := range db.transactions { + for i, txn := range db.txs { if txn == t { - db.transactions = append(db.transactions[:i], db.transactions[i+1:]...) + db.txs = append(db.txs[:i], db.txs[i+1:]...) break } } } -// Do executes a function within the context of a RWTransaction. +// Do executes a function within the context of a RWTx. // If no error is returned from the function then the transaction is committed. // If an error is returned then the entire transaction is rolled back. // Any error that is returned from the function or returned from the commit is // returned from the Do() method. -func (db *DB) Do(fn func(*RWTransaction) error) error { - t, err := db.RWTransaction() +func (db *DB) Do(fn func(*RWTx) error) error { + t, err := db.RWTx() if err != nil { return err } @@ -359,10 +359,10 @@ func (db *DB) Do(fn func(*RWTransaction) error) error { return t.Commit() } -// With executes a function within the context of a Transaction. +// With executes a function within the context of a transaction. // Any error that is returned from the function is returned from the With() method. -func (db *DB) With(fn func(*Transaction) error) error { - t, err := db.Transaction() +func (db *DB) With(fn func(*Tx) error) error { + t, err := db.Tx() if err != nil { return err } @@ -375,7 +375,7 @@ func (db *DB) With(fn func(*Transaction) error) error { // ForEach executes a function for each key/value pair in a bucket. // An error is returned if the bucket cannot be found. func (db *DB) ForEach(name string, fn func(k, v []byte) error) error { - return db.With(func(t *Transaction) error { + return db.With(func(t *Tx) error { b := t.Bucket(name) if b == nil { return ErrBucketNotFound @@ -387,7 +387,7 @@ func (db *DB) ForEach(name string, fn func(k, v []byte) error) error { // Bucket retrieves a reference to a bucket. // This is typically useful for checking the existence of a bucket. func (db *DB) Bucket(name string) (*Bucket, error) { - t, err := db.Transaction() + t, err := db.Tx() if err != nil { return nil, err } @@ -397,7 +397,7 @@ func (db *DB) Bucket(name string) (*Bucket, error) { // Buckets retrieves a list of all buckets in the database. func (db *DB) Buckets() ([]*Bucket, error) { - t, err := db.Transaction() + t, err := db.Tx() if err != nil { return nil, err } @@ -409,7 +409,7 @@ func (db *DB) Buckets() ([]*Bucket, error) { // This function can return an error if the bucket already exists, if the name // is blank, or the bucket name is too long. func (db *DB) CreateBucket(name string) error { - return db.Do(func(t *RWTransaction) error { + return db.Do(func(t *RWTx) error { return t.CreateBucket(name) }) } @@ -417,7 +417,7 @@ func (db *DB) CreateBucket(name string) error { // CreateBucketIfNotExists creates a new bucket with the given name if it doesn't already exist. // This function can return an error if the name is blank, or the bucket name is too long. func (db *DB) CreateBucketIfNotExists(name string) error { - return db.Do(func(t *RWTransaction) error { + return db.Do(func(t *RWTx) error { return t.CreateBucketIfNotExists(name) }) } @@ -425,7 +425,7 @@ func (db *DB) CreateBucketIfNotExists(name string) error { // DeleteBucket removes a bucket from the database. // Returns an error if the bucket does not exist. func (db *DB) DeleteBucket(name string) error { - return db.Do(func(t *RWTransaction) error { + return db.Do(func(t *RWTx) error { return t.DeleteBucket(name) }) } @@ -434,7 +434,7 @@ func (db *DB) DeleteBucket(name string) error { // This function can return an error if the bucket does not exist. func (db *DB) NextSequence(name string) (int, error) { var seq int - err := db.Do(func(t *RWTransaction) error { + err := db.Do(func(t *RWTx) error { b := t.Bucket(name) if b == nil { return ErrBucketNotFound @@ -453,7 +453,7 @@ func (db *DB) NextSequence(name string) (int, error) { // Get retrieves the value for a key in a bucket. // Returns an error if the key does not exist. func (db *DB) Get(name string, key []byte) ([]byte, error) { - t, err := db.Transaction() + t, err := db.Tx() if err != nil { return nil, err } @@ -482,7 +482,7 @@ func (db *DB) Get(name string, key []byte) ([]byte, error) { // Put sets the value for a key in a bucket. // Returns an error if the bucket is not found, if key is blank, if the key is too large, or if the value is too large. func (db *DB) Put(name string, key []byte, value []byte) error { - return db.Do(func(t *RWTransaction) error { + return db.Do(func(t *RWTx) error { b := t.Bucket(name) if b == nil { return ErrBucketNotFound @@ -494,7 +494,7 @@ func (db *DB) Put(name string, key []byte, value []byte) error { // Delete removes a key from a bucket. // Returns an error if the bucket cannot be found. func (db *DB) Delete(name string, key []byte) error { - return db.Do(func(t *RWTransaction) error { + return db.Do(func(t *RWTx) error { b := t.Bucket(name) if b == nil { return ErrBucketNotFound @@ -508,7 +508,7 @@ func (db *DB) Delete(name string, key []byte) error { // using the database while a copy is in progress. func (db *DB) Copy(w io.Writer) error { // Maintain a reader transaction so pages don't get reclaimed. - t, err := db.Transaction() + t, err := db.Tx() if err != nil { return err } @@ -549,15 +549,15 @@ func (db *DB) Stat() (*Stat, error) { db.mmaplock.RLock() var s = &Stat{ - MmapSize: len(db.data), - TransactionCount: len(db.transactions), + MmapSize: len(db.data), + TxCount: len(db.txs), } // Release locks. db.mmaplock.RUnlock() db.metalock.Unlock() - err := db.Do(func(t *RWTransaction) error { + err := db.Do(func(t *RWTx) error { s.PageCount = int(t.meta.pgid) s.FreePageCount = len(db.freelist.all()) s.PageSize = db.pageSize @@ -582,7 +582,7 @@ func (db *DB) pageInBuffer(b []byte, id pgid) *page { // meta retrieves the current meta page reference. func (db *DB) meta() *meta { - if db.meta0.txnid > db.meta1.txnid { + if db.meta0.txid > db.meta1.txid { return db.meta0 } return db.meta1 @@ -601,7 +601,7 @@ func (db *DB) allocate(count int) (*page, error) { } // Resize mmap() if we're at the end. - p.id = db.rwtransaction.meta.pgid + p.id = db.rwtx.meta.pgid var minsz = int((p.id+pgid(count))+1) * db.pageSize if minsz >= len(db.data) { if err := db.mmap(minsz); err != nil { @@ -610,7 +610,7 @@ func (db *DB) allocate(count int) (*page, error) { } // Move the page id high water mark. - db.rwtransaction.meta.pgid += pgid(count) + db.rwtx.meta.pgid += pgid(count) return p, nil } @@ -634,6 +634,6 @@ type Stat struct { // resize it. MmapSize int - // TransactionCount is the total number of reader transactions. - TransactionCount int + // TxCount is the total number of reader transactions. + TxCount int } diff --git a/db_test.go b/db_test.go index c8a8267..029d248 100644 --- a/db_test.go +++ b/db_test.go @@ -156,9 +156,9 @@ func TestDBCorruptMeta0(t *testing.T) { } // Ensure that a database cannot open a transaction when it's not open. -func TestDBTransactionErrDatabaseNotOpen(t *testing.T) { +func TestDBTxErrDatabaseNotOpen(t *testing.T) { withDB(func(db *DB, path string) { - txn, err := db.Transaction() + txn, err := db.Tx() assert.Nil(t, txn) assert.Equal(t, err, ErrDatabaseNotOpen) }) @@ -173,9 +173,9 @@ func TestDBDeleteFromMissingBucket(t *testing.T) { } // Ensure a database can provide a transactional block. -func TestDBTransactionBlock(t *testing.T) { +func TestDBTxBlock(t *testing.T) { withOpenDB(func(db *DB, path string) { - err := db.Do(func(txn *RWTransaction) error { + err := db.Do(func(txn *RWTx) error { txn.CreateBucket("widgets") b := txn.Bucket("widgets") b.Put([]byte("foo"), []byte("bar")) @@ -192,9 +192,9 @@ func TestDBTransactionBlock(t *testing.T) { } // Ensure a closed database returns an error while running a transaction block -func TestDBTransactionBlockWhileClosed(t *testing.T) { +func TestDBTxBlockWhileClosed(t *testing.T) { withDB(func(db *DB, path string) { - err := db.Do(func(txn *RWTransaction) error { + err := db.Do(func(txn *RWTx) error { txn.CreateBucket("widgets") return nil }) @@ -276,7 +276,7 @@ func TestDBCopyFile(t *testing.T) { // Ensure the database can return stats about itself. func TestDBStat(t *testing.T) { withOpenDB(func(db *DB, path string) { - db.Do(func(txn *RWTransaction) error { + db.Do(func(txn *RWTx) error { txn.CreateBucket("widgets") b := txn.Bucket("widgets") for i := 0; i < 10000; i++ { @@ -290,9 +290,9 @@ func TestDBStat(t *testing.T) { db.Delete("widgets", []byte("1000")) // Open some readers. - t0, _ := db.Transaction() - t1, _ := db.Transaction() - t2, _ := db.Transaction() + t0, _ := db.Tx() + t1, _ := db.Tx() + t2, _ := db.Tx() t2.Close() // Obtain stats. @@ -302,7 +302,7 @@ func TestDBStat(t *testing.T) { assert.Equal(t, stat.FreePageCount, 2) assert.Equal(t, stat.PageSize, 4096) assert.Equal(t, stat.MmapSize, 4194304) - assert.Equal(t, stat.TransactionCount, 2) + assert.Equal(t, stat.TxCount, 2) // Close readers. t0.Close() diff --git a/doc.go b/doc.go index d7f3ec1..ec576a2 100644 --- a/doc.go +++ b/doc.go @@ -2,7 +2,7 @@ Package bolt implements a low-level key/value store in pure Go. It supports fully serializable transactions, ACID semantics, and lock-free MVCC with multiple readers and a single writer. Bolt can be used for projects that -want a simple data store without the need to add large dependencies such as +want a simple data store without the need to add large dependencies such as Postgres or MySQL. Bolt is a single-level, zero-copy, B+tree data store. This means that Bolt is @@ -14,15 +14,14 @@ The design of Bolt is based on Howard Chu's LMDB database project. Basics -There are only a few types in Bolt: DB, Bucket, Transaction, RWTransaction, and -Cursor. The DB is a collection of buckets and is represented by a single file -on disk. A bucket is a collection of unique keys that are associated with values. +There are only a few types in Bolt: DB, Bucket, Tx, RWTx, and Cursor. The DB is +a collection of buckets and is represented by a single file on disk. A bucket is +a collection of unique keys that are associated with values. -Transactions provide read-only access to data inside the database. They can -retrieve key/value pairs and can use Cursors to iterate over the entire dataset. -RWTransactions provide read-write access to the database. They can create and -delete buckets and they can insert and remove keys. Only one RWTransaction is -allowed at a time. +Txs provide read-only access to data inside the database. They can retrieve +key/value pairs and can use Cursors to iterate over the entire dataset. RWTxs +provide read-write access to the database. They can create and delete buckets +and they can insert and remove keys. Only one RWTx is allowed at a time. Caveats diff --git a/example_test.go b/example_test.go index b4fac38..82db552 100644 --- a/example_test.go +++ b/example_test.go @@ -67,7 +67,7 @@ func ExampleDB_Do() { defer db.Close() // Execute several commands within a write transaction. - err := db.Do(func(t *RWTransaction) error { + err := db.Do(func(t *RWTx) error { if err := t.CreateBucket("widgets"); err != nil { return err } @@ -100,7 +100,7 @@ func ExampleDB_With() { db.Put("people", []byte("susy"), []byte("que")) // Access data from within a read-only transactional block. - db.With(func(t *Transaction) error { + db.With(func(t *Tx) error { v := t.Bucket("people").Get([]byte("john")) fmt.Printf("John's last name is %s.\n", string(v)) return nil @@ -134,17 +134,17 @@ func ExampleDB_ForEach() { // A liger is awesome. } -func ExampleRWTransaction() { +func ExampleRWTx() { // Open the database. var db DB - db.Open("/tmp/bolt/rwtransaction.db", 0666) + db.Open("/tmp/bolt/rwtx.db", 0666) defer db.Close() // Create a bucket. db.CreateBucket("widgets") // Create several keys in a transaction. - rwtxn, _ := db.RWTransaction() + rwtxn, _ := db.RWTx() b := rwtxn.Bucket("widgets") b.Put([]byte("john"), []byte("blue")) b.Put([]byte("abby"), []byte("red")) @@ -152,7 +152,7 @@ func ExampleRWTransaction() { rwtxn.Commit() // Iterate over the values in sorted key order. - txn, _ := db.Transaction() + txn, _ := db.Tx() c := txn.Bucket("widgets").Cursor() for k, v := c.First(); k != nil; k, v = c.Next() { fmt.Printf("%s likes %s\n", string(k), string(v)) @@ -165,10 +165,10 @@ func ExampleRWTransaction() { // zephyr likes purple } -func ExampleRWTransaction_rollback() { +func ExampleRWTx_rollback() { // Open the database. var db DB - db.Open("/tmp/bolt/rwtransaction_rollback.db", 0666) + db.Open("/tmp/bolt/rwtx_rollback.db", 0666) defer db.Close() // Create a bucket. @@ -178,7 +178,7 @@ func ExampleRWTransaction_rollback() { db.Put("widgets", []byte("foo"), []byte("bar")) // Update the key but rollback the transaction so it never saves. - rwtxn, _ := db.RWTransaction() + rwtxn, _ := db.RWTx() b := rwtxn.Bucket("widgets") b.Put([]byte("foo"), []byte("baz")) rwtxn.Rollback() diff --git a/freelist.go b/freelist.go index 3f5cf1c..636ed22 100644 --- a/freelist.go +++ b/freelist.go @@ -9,7 +9,7 @@ import ( // It also tracks pages that have been freed but are still in use by open transactions. type freelist struct { ids []pgid - pending map[txnid][]pgid + pending map[txid][]pgid } // all returns a list of all free ids and all pending ids in one sorted list. @@ -50,19 +50,19 @@ func (f *freelist) allocate(n int) pgid { } // free releases a page and its overflow for a given transaction id. -func (f *freelist) free(txnid txnid, p *page) { - var ids = f.pending[txnid] +func (f *freelist) free(txid txid, p *page) { + var ids = f.pending[txid] _assert(p.id > 1, "cannot free page 0 or 1: %d", p.id) for i := 0; i < int(p.overflow+1); i++ { ids = append(ids, p.id+pgid(i)) } - f.pending[txnid] = ids + f.pending[txid] = ids } // release moves all page ids for a transaction id (or older) to the freelist. -func (f *freelist) release(txnid txnid) { +func (f *freelist) release(txid txid) { for tid, ids := range f.pending { - if tid <= txnid { + if tid <= txid { f.ids = append(f.ids, ids...) delete(f.pending, tid) } diff --git a/freelist_test.go b/freelist_test.go index d452a2e..8421392 100644 --- a/freelist_test.go +++ b/freelist_test.go @@ -9,21 +9,21 @@ import ( // Ensure that a page is added to a transaction's freelist. func TestFreelistFree(t *testing.T) { - f := &freelist{pending: make(map[txnid][]pgid)} + f := &freelist{pending: make(map[txid][]pgid)} f.free(100, &page{id: 12}) assert.Equal(t, f.pending[100], []pgid{12}) } // Ensure that a page and its overflow is added to a transaction's freelist. func TestFreelistFreeOverflow(t *testing.T) { - f := &freelist{pending: make(map[txnid][]pgid)} + f := &freelist{pending: make(map[txid][]pgid)} f.free(100, &page{id: 12, overflow: 3}) assert.Equal(t, f.pending[100], []pgid{12, 13, 14, 15}) } // Ensure that a transaction's free pages can be released. func TestFreelistRelease(t *testing.T) { - f := &freelist{pending: make(map[txnid][]pgid)} + f := &freelist{pending: make(map[txid][]pgid)} f.free(100, &page{id: 12, overflow: 1}) f.free(100, &page{id: 9}) f.free(102, &page{id: 39}) @@ -61,7 +61,7 @@ func TestFreelistRead(t *testing.T) { ids[1] = 50 // Deserialize page into a freelist. - f := &freelist{pending: make(map[txnid][]pgid)} + f := &freelist{pending: make(map[txid][]pgid)} f.read(page) // Ensure that there are two page ids in the freelist. @@ -74,14 +74,14 @@ func TestFreelistRead(t *testing.T) { func TestFreelistWrite(t *testing.T) { // Create a freelist and write it to a page. var buf [4096]byte - f := &freelist{ids: []pgid{12, 39}, pending: make(map[txnid][]pgid)} + f := &freelist{ids: []pgid{12, 39}, pending: make(map[txid][]pgid)} f.pending[100] = []pgid{28, 11} f.pending[101] = []pgid{3} p := (*page)(unsafe.Pointer(&buf[0])) f.write(p) // Read the page back out. - f2 := &freelist{pending: make(map[txnid][]pgid)} + f2 := &freelist{pending: make(map[txid][]pgid)} f2.read(p) // Ensure that the freelist is correct. diff --git a/functional_test.go b/functional_test.go index 61f09bc..20af8fc 100644 --- a/functional_test.go +++ b/functional_test.go @@ -12,7 +12,7 @@ import ( ) // Ensure that multiple threads can use the DB without race detector errors. -func TestParallelTransactions(t *testing.T) { +func TestParallelTxs(t *testing.T) { var mutex sync.RWMutex err := quick.Check(func(numReaders, batchSize uint, items testdata) bool { @@ -45,7 +45,7 @@ func TestParallelTransactions(t *testing.T) { go func() { mutex.RLock() local := current - txn, err := db.Transaction() + txn, err := db.Tx() mutex.RUnlock() if err == ErrDatabaseNotOpen { wg.Done() @@ -83,7 +83,7 @@ func TestParallelTransactions(t *testing.T) { pending = pending[currentBatchSize:] // Start write transaction. - txn, err := db.RWTransaction() + txn, err := db.RWTx() if !assert.NoError(t, err) { t.FailNow() } diff --git a/meta.go b/meta.go index 643d339..cee2d29 100644 --- a/meta.go +++ b/meta.go @@ -10,7 +10,7 @@ type meta struct { buckets pgid freelist pgid pgid pgid - txnid txnid + txid txid } // validate checks the marker bytes and version of the meta page to ensure it matches this binary. @@ -31,13 +31,13 @@ func (m *meta) copy(dest *meta) { dest.buckets = m.buckets dest.freelist = m.freelist dest.pgid = m.pgid - dest.txnid = m.txnid + dest.txid = m.txid } // write writes the meta onto a page. func (m *meta) write(p *page) { // Page id is either going to be 0 or 1 which we can determine by the Txn ID. - p.id = pgid(m.txnid % 2) + p.id = pgid(m.txid % 2) p.flags |= metaPageFlag m.copy(p.meta()) diff --git a/node.go b/node.go index 68f651e..f0929c7 100644 --- a/node.go +++ b/node.go @@ -8,14 +8,14 @@ import ( // node represents an in-memory, deserialized page. type node struct { - transaction *RWTransaction - isLeaf bool - unbalanced bool - key []byte - depth int - pgid pgid - parent *node - inodes inodes + tx *RWTx + isLeaf bool + unbalanced bool + key []byte + depth int + pgid pgid + parent *node + inodes inodes } // minKeys returns the minimum number of inodes this node should have. @@ -56,7 +56,7 @@ func (n *node) root() *node { // childAt returns the child node at a given index. func (n *node) childAt(index int) *node { _assert(!n.isLeaf, "invalid childAt(%d) on a leaf node", index) - return n.transaction.node(n.inodes[index].pgid, n) + return n.tx.node(n.inodes[index].pgid, n) } // childIndex returns the index of a given child node. @@ -214,7 +214,7 @@ func (n *node) split(pageSize int) []*node { if len(current.inodes) >= minKeysPerPage && i < len(inodes)-minKeysPerPage && size+elemSize > threshold { size = pageHeaderSize nodes = append(nodes, current) - current = &node{transaction: n.transaction, isLeaf: n.isLeaf} + current = &node{tx: n.tx, isLeaf: n.isLeaf} } size += elemSize @@ -234,7 +234,7 @@ func (n *node) rebalance() { n.unbalanced = false // Ignore if node is above threshold (25%) and has enough keys. - var threshold = n.transaction.db.pageSize / 4 + var threshold = n.tx.db.pageSize / 4 if n.size() > threshold && len(n.inodes) > n.minKeys() { return } @@ -244,20 +244,20 @@ func (n *node) rebalance() { // If root node is a branch and only has one node then collapse it. if !n.isLeaf && len(n.inodes) == 1 { // Move child's children up. - child := n.transaction.nodes[n.inodes[0].pgid] + child := n.tx.nodes[n.inodes[0].pgid] n.isLeaf = child.isLeaf n.inodes = child.inodes[:] // Reparent all child nodes being moved. for _, inode := range n.inodes { - if child, ok := n.transaction.nodes[inode.pgid]; ok { + if child, ok := n.tx.nodes[inode.pgid]; ok { child.parent = n } } // Remove old child. child.parent = nil - delete(n.transaction.nodes, child.pgid) + delete(n.tx.nodes, child.pgid) } return @@ -278,7 +278,7 @@ func (n *node) rebalance() { if target.numChildren() > target.minKeys() { if useNextSibling { // Reparent and move node. - if child, ok := n.transaction.nodes[target.inodes[0].pgid]; ok { + if child, ok := n.tx.nodes[target.inodes[0].pgid]; ok { child.parent = n } n.inodes = append(n.inodes, target.inodes[0]) @@ -289,7 +289,7 @@ func (n *node) rebalance() { target.key = target.inodes[0].key } else { // Reparent and move node. - if child, ok := n.transaction.nodes[target.inodes[len(target.inodes)-1].pgid]; ok { + if child, ok := n.tx.nodes[target.inodes[len(target.inodes)-1].pgid]; ok { child.parent = n } n.inodes = append(n.inodes, inode{}) @@ -309,7 +309,7 @@ func (n *node) rebalance() { if useNextSibling { // Reparent all child nodes being moved. for _, inode := range target.inodes { - if child, ok := n.transaction.nodes[inode.pgid]; ok { + if child, ok := n.tx.nodes[inode.pgid]; ok { child.parent = n } } @@ -317,11 +317,11 @@ func (n *node) rebalance() { // Copy over inodes from target and remove target. n.inodes = append(n.inodes, target.inodes...) n.parent.del(target.key) - delete(n.transaction.nodes, target.pgid) + delete(n.tx.nodes, target.pgid) } else { // Reparent all child nodes being moved. for _, inode := range n.inodes { - if child, ok := n.transaction.nodes[inode.pgid]; ok { + if child, ok := n.tx.nodes[inode.pgid]; ok { child.parent = target } } @@ -330,7 +330,7 @@ func (n *node) rebalance() { target.inodes = append(target.inodes, n.inodes...) n.parent.del(n.key) n.parent.put(target.key, target.inodes[0].key, nil, target.pgid) - delete(n.transaction.nodes, n.pgid) + delete(n.tx.nodes, n.pgid) } // Either this node or the target node was deleted from the parent so rebalance it. diff --git a/rwtransaction.go b/rwtransaction.go index 776cf55..0c670d9 100644 --- a/rwtransaction.go +++ b/rwtransaction.go @@ -5,29 +5,29 @@ import ( "unsafe" ) -// RWTransaction represents a transaction that can read and write data. +// RWTx represents a transaction that can read and write data. // Only one read/write transaction can be active for a database at a time. -// RWTransaction is composed of a read-only Transaction so it can also use -// functions provided by Transaction. -type RWTransaction struct { - Transaction +// RWTx is composed of a read-only transaction so it can also use +// functions provided by Tx. +type RWTx struct { + Tx pending []*node } // init initializes the transaction. -func (t *RWTransaction) init(db *DB) { - t.Transaction.init(db) - t.Transaction.rwtransaction = t +func (t *RWTx) init(db *DB) { + t.Tx.init(db) + t.Tx.rwtx = t t.pages = make(map[pgid]*page) t.nodes = make(map[pgid]*node) // Increment the transaction id. - t.meta.txnid += txnid(1) + t.meta.txid += txid(1) } // CreateBucket creates a new bucket. // Returns an error if the bucket already exists, if the bucket name is blank, or if the bucket name is too long. -func (t *RWTransaction) CreateBucket(name string) error { +func (t *RWTx) CreateBucket(name string) error { // Check if bucket already exists. if b := t.Bucket(name); b != nil { return ErrBucketExists @@ -52,7 +52,7 @@ func (t *RWTransaction) CreateBucket(name string) error { // CreateBucketIfNotExists creates a new bucket if it doesn't already exist. // Returns an error if the bucket name is blank, or if the bucket name is too long. -func (t *RWTransaction) CreateBucketIfNotExists(name string) error { +func (t *RWTx) CreateBucketIfNotExists(name string) error { err := t.CreateBucket(name) if err != nil && err != ErrBucketExists { return err @@ -62,7 +62,7 @@ func (t *RWTransaction) CreateBucketIfNotExists(name string) error { // DeleteBucket deletes a bucket. // Returns an error if the bucket cannot be found. -func (t *RWTransaction) DeleteBucket(name string) error { +func (t *RWTx) DeleteBucket(name string) error { b := t.Bucket(name) if b == nil { return ErrBucketNotFound @@ -81,7 +81,7 @@ func (t *RWTransaction) DeleteBucket(name string) error { // Commit writes all changes to disk and updates the meta page. // Returns an error if a disk write error occurs. -func (t *RWTransaction) Commit() error { +func (t *RWTx) Commit() error { if t.db == nil { return nil } @@ -118,11 +118,11 @@ func (t *RWTransaction) Commit() error { } // Rollback closes the transaction and ignores all previous updates. -func (t *RWTransaction) Rollback() { +func (t *RWTx) Rollback() { t.close() } -func (t *RWTransaction) close() { +func (t *RWTx) close() { if t.db != nil { t.db.rwlock.Unlock() t.db = nil @@ -130,7 +130,7 @@ func (t *RWTransaction) close() { } // allocate returns a contiguous block of memory starting at a given page. -func (t *RWTransaction) allocate(count int) (*page, error) { +func (t *RWTx) allocate(count int) (*page, error) { p, err := t.db.allocate(count) if err != nil { return nil, err @@ -143,14 +143,14 @@ func (t *RWTransaction) allocate(count int) (*page, error) { } // rebalance attempts to balance all nodes. -func (t *RWTransaction) rebalance() { +func (t *RWTx) rebalance() { for _, n := range t.nodes { n.rebalance() } } // spill writes all the nodes to dirty pages. -func (t *RWTransaction) spill() error { +func (t *RWTx) spill() error { // Keep track of the current root nodes. // We will update this at the end once all nodes are created. type root struct { @@ -182,7 +182,7 @@ func (t *RWTransaction) spill() error { // If this is a root node that split then create a parent node. if n.parent == nil && len(newNodes) > 1 { - n.parent = &node{transaction: t, isLeaf: false} + n.parent = &node{tx: t, isLeaf: false} nodes = append(nodes, n.parent) } @@ -233,7 +233,7 @@ func (t *RWTransaction) spill() error { } // write writes any dirty pages to disk. -func (t *RWTransaction) write() error { +func (t *RWTx) write() error { // Sort pages by id. pages := make(pages, 0, len(t.pages)) for _, p := range t.pages { @@ -258,7 +258,7 @@ func (t *RWTransaction) write() error { } // writeMeta writes the meta to the disk. -func (t *RWTransaction) writeMeta() error { +func (t *RWTx) writeMeta() error { // Create a temporary buffer for the meta page. buf := make([]byte, t.db.pageSize) p := t.db.pageInBuffer(buf, 0) @@ -271,14 +271,14 @@ func (t *RWTransaction) writeMeta() error { } // node creates a node from a page and associates it with a given parent. -func (t *RWTransaction) node(pgid pgid, parent *node) *node { +func (t *RWTx) node(pgid pgid, parent *node) *node { // Retrieve node if it has already been fetched. - if n := t.Transaction.node(pgid); n != nil { + if n := t.Tx.node(pgid); n != nil { return n } // Otherwise create a branch and cache it. - n := &node{transaction: t, parent: parent} + n := &node{tx: t, parent: parent} if n.parent != nil { n.depth = n.parent.depth + 1 } @@ -289,7 +289,7 @@ func (t *RWTransaction) node(pgid pgid, parent *node) *node { } // dereference removes all references to the old mmap. -func (t *RWTransaction) dereference() { +func (t *RWTx) dereference() { for _, n := range t.nodes { n.dereference() } diff --git a/rwtransaction_test.go b/rwtransaction_test.go index e45ec10..c94f534 100644 --- a/rwtransaction_test.go +++ b/rwtransaction_test.go @@ -9,31 +9,31 @@ import ( "github.com/stretchr/testify/assert" ) -// Ensure that a RWTransaction can be retrieved. -func TestRWTransaction(t *testing.T) { +// Ensure that a RWTx can be retrieved. +func TestRWTx(t *testing.T) { withOpenDB(func(db *DB, path string) { - txn, err := db.RWTransaction() + txn, err := db.RWTx() assert.NotNil(t, txn) assert.NoError(t, err) assert.Equal(t, txn.DB(), db) }) } -// Ensure that opening a RWTransaction while the DB is closed returns an error. -func TestRWTransactionOpenWithClosedDB(t *testing.T) { +// Ensure that opening a RWTx while the DB is closed returns an error. +func TestRWTxOpenWithClosedDB(t *testing.T) { withDB(func(db *DB, path string) { - txn, err := db.RWTransaction() + txn, err := db.RWTx() assert.Equal(t, err, ErrDatabaseNotOpen) assert.Nil(t, txn) }) } // Ensure that retrieving all buckets returns writable buckets. -func TestRWTransactionBuckets(t *testing.T) { +func TestRWTxBuckets(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") db.CreateBucket("woojits") - db.Do(func(txn *RWTransaction) error { + db.Do(func(txn *RWTx) error { buckets := txn.Buckets() assert.Equal(t, len(buckets), 2) assert.Equal(t, buckets[0].Name(), "widgets") @@ -50,7 +50,7 @@ func TestRWTransactionBuckets(t *testing.T) { } // Ensure that a bucket can be created and retrieved. -func TestRWTransactionCreateBucket(t *testing.T) { +func TestRWTxCreateBucket(t *testing.T) { withOpenDB(func(db *DB, path string) { // Create a bucket. err := db.CreateBucket("widgets") @@ -64,7 +64,7 @@ func TestRWTransactionCreateBucket(t *testing.T) { } // Ensure that a bucket can be created if it doesn't already exist. -func TestRWTransactionCreateBucketIfNotExists(t *testing.T) { +func TestRWTxCreateBucketIfNotExists(t *testing.T) { withOpenDB(func(db *DB, path string) { assert.NoError(t, db.CreateBucketIfNotExists("widgets")) assert.NoError(t, db.CreateBucketIfNotExists("widgets")) @@ -78,7 +78,7 @@ func TestRWTransactionCreateBucketIfNotExists(t *testing.T) { } // Ensure that a bucket cannot be created twice. -func TestRWTransactionRecreateBucket(t *testing.T) { +func TestRWTxRecreateBucket(t *testing.T) { withOpenDB(func(db *DB, path string) { // Create a bucket. err := db.CreateBucket("widgets") @@ -91,7 +91,7 @@ func TestRWTransactionRecreateBucket(t *testing.T) { } // Ensure that a bucket is created with a non-blank name. -func TestRWTransactionCreateBucketWithoutName(t *testing.T) { +func TestRWTxCreateBucketWithoutName(t *testing.T) { withOpenDB(func(db *DB, path string) { err := db.CreateBucket("") assert.Equal(t, err, ErrBucketNameRequired) @@ -99,7 +99,7 @@ func TestRWTransactionCreateBucketWithoutName(t *testing.T) { } // Ensure that a bucket name is not too long. -func TestRWTransactionCreateBucketWithLongName(t *testing.T) { +func TestRWTxCreateBucketWithLongName(t *testing.T) { withOpenDB(func(db *DB, path string) { err := db.CreateBucket(strings.Repeat("X", 255)) assert.NoError(t, err) @@ -110,7 +110,7 @@ func TestRWTransactionCreateBucketWithLongName(t *testing.T) { } // Ensure that a bucket can be deleted. -func TestRWTransactionDeleteBucket(t *testing.T) { +func TestRWTxDeleteBucket(t *testing.T) { withOpenDB(func(db *DB, path string) { // Create a bucket and add a value. db.CreateBucket("widgets") @@ -136,7 +136,7 @@ func TestRWTransactionDeleteBucket(t *testing.T) { } // Ensure that an error is returned when deleting from a bucket that doesn't exist. -func TestRWTransactionDeleteBucketNotFound(t *testing.T) { +func TestRWTxDeleteBucketNotFound(t *testing.T) { withOpenDB(func(db *DB, path string) { err := db.DeleteBucket("widgets") assert.Equal(t, err, ErrBucketNotFound) @@ -144,19 +144,19 @@ func TestRWTransactionDeleteBucketNotFound(t *testing.T) { } // Benchmark the performance of bulk put transactions in random order. -func BenchmarkRWTransactionPutRandom(b *testing.B) { +func BenchmarkRWTxPutRandom(b *testing.B) { indexes := rand.Perm(b.N) value := []byte(strings.Repeat("0", 64)) withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") - var txn *RWTransaction + var txn *RWTx var bucket *Bucket for i := 0; i < b.N; i++ { if i%1000 == 0 { if txn != nil { txn.Commit() } - txn, _ = db.RWTransaction() + txn, _ = db.RWTx() bucket = txn.Bucket("widgets") } bucket.Put([]byte(strconv.Itoa(indexes[i])), value) @@ -166,11 +166,11 @@ func BenchmarkRWTransactionPutRandom(b *testing.B) { } // Benchmark the performance of bulk put transactions in sequential order. -func BenchmarkRWTransactionPutSequential(b *testing.B) { +func BenchmarkRWTxPutSequential(b *testing.B) { value := []byte(strings.Repeat("0", 64)) withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") - db.Do(func(txn *RWTransaction) error { + db.Do(func(txn *RWTx) error { bucket := txn.Bucket("widgets") for i := 0; i < b.N; i++ { bucket.Put([]byte(strconv.Itoa(i)), value) diff --git a/transaction.go b/transaction.go index 857defb..91ab730 100644 --- a/transaction.go +++ b/transaction.go @@ -1,26 +1,26 @@ package bolt -// Transaction represents a read-only transaction on the database. +// Tx represents a read-only transaction on the database. // It can be used for retrieving values for keys as well as creating cursors for // iterating over the data. // // IMPORTANT: You must close transactions when you are done with them. Pages // can not be reclaimed by the writer until no more transactions are using them. // A long running read transaction can cause the database to quickly grow. -type Transaction struct { - db *DB - rwtransaction *RWTransaction - meta *meta - buckets *buckets - nodes map[pgid]*node - pages map[pgid]*page +type Tx struct { + db *DB + rwtx *RWTx + meta *meta + buckets *buckets + nodes map[pgid]*node + pages map[pgid]*page } -// txnid represents the internal transaction identifier. -type txnid uint64 +// txid represents the internal transaction identifier. +type txid uint64 // init initializes the transaction and associates it with a database. -func (t *Transaction) init(db *DB) { +func (t *Tx) init(db *DB) { t.db = db t.pages = nil @@ -34,52 +34,52 @@ func (t *Transaction) init(db *DB) { } // id returns the transaction id. -func (t *Transaction) id() txnid { - return t.meta.txnid +func (t *Tx) id() txid { + return t.meta.txid } // Close closes the transaction and releases any pages it is using. -func (t *Transaction) Close() { +func (t *Tx) Close() { if t.db != nil { - if t.rwtransaction != nil { - t.rwtransaction.Rollback() + if t.rwtx != nil { + t.rwtx.Rollback() } else { - t.db.removeTransaction(t) + t.db.removeTx(t) t.db = nil } } } // DB returns a reference to the database that created the transaction. -func (t *Transaction) DB() *DB { +func (t *Tx) DB() *DB { return t.db } // Bucket retrieves a bucket by name. // Returns nil if the bucket does not exist. -func (t *Transaction) Bucket(name string) *Bucket { +func (t *Tx) Bucket(name string) *Bucket { b := t.buckets.get(name) if b == nil { return nil } return &Bucket{ - bucket: b, - name: name, - transaction: t, - rwtransaction: t.rwtransaction, + bucket: b, + name: name, + tx: t, + rwtx: t.rwtx, } } // Buckets retrieves a list of all buckets. -func (t *Transaction) Buckets() []*Bucket { +func (t *Tx) Buckets() []*Bucket { buckets := make([]*Bucket, 0, len(t.buckets.items)) for name, b := range t.buckets.items { bucket := &Bucket{ - bucket: b, - name: name, - transaction: t, - rwtransaction: t.rwtransaction, + bucket: b, + name: name, + tx: t, + rwtx: t.rwtx, } buckets = append(buckets, bucket) } @@ -88,7 +88,7 @@ func (t *Transaction) Buckets() []*Bucket { // page returns a reference to the page with a given id. // If page has been written to then a temporary bufferred page is returned. -func (t *Transaction) page(id pgid) *page { +func (t *Tx) page(id pgid) *page { // Check the dirty pages first. if t.pages != nil { if p, ok := t.pages[id]; ok { @@ -101,7 +101,7 @@ func (t *Transaction) page(id pgid) *page { } // node returns a reference to the in-memory node for a given page, if it exists. -func (t *Transaction) node(id pgid) *node { +func (t *Tx) node(id pgid) *node { if t.nodes == nil { return nil } @@ -110,7 +110,7 @@ func (t *Transaction) node(id pgid) *node { // pageNode returns the in-memory node, if it exists. // Otherwise returns the underlying page. -func (t *Transaction) pageNode(id pgid) (*page, *node) { +func (t *Tx) pageNode(id pgid) (*page, *node) { if n := t.node(id); n != nil { return nil, n } @@ -118,7 +118,7 @@ func (t *Transaction) pageNode(id pgid) (*page, *node) { } // forEachPage iterates over every page within a given page and executes a function. -func (t *Transaction) forEachPage(pgid pgid, depth int, fn func(*page, int)) { +func (t *Tx) forEachPage(pgid pgid, depth int, fn func(*page, int)) { p := t.page(pgid) // Execute function. diff --git a/transaction_test.go b/transaction_test.go index 04cb44b..59f4dd5 100644 --- a/transaction_test.go +++ b/transaction_test.go @@ -14,7 +14,7 @@ import ( ) // Ensure that the database can retrieve a list of buckets. -func TestTransactionBuckets(t *testing.T) { +func TestTxBuckets(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("foo") db.CreateBucket("bar") @@ -28,8 +28,8 @@ func TestTransactionBuckets(t *testing.T) { }) } -// Ensure that a Transaction can retrieve a bucket. -func TestTransactionBucketMissing(t *testing.T) { +// Ensure that a Tx can retrieve a bucket. +func TestTxBucketMissing(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") b, err := db.Bucket("widgets") @@ -40,8 +40,8 @@ func TestTransactionBucketMissing(t *testing.T) { }) } -// Ensure that a Transaction retrieving a non-existent key returns nil. -func TestTransactionGetMissing(t *testing.T) { +// Ensure that a Tx retrieving a non-existent key returns nil. +func TestTxGetMissing(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") db.Put("widgets", []byte("foo"), []byte("bar")) @@ -51,11 +51,11 @@ func TestTransactionGetMissing(t *testing.T) { }) } -// Ensure that a Transaction cursor can iterate over an empty bucket without error. -func TestTransactionCursorEmptyBucket(t *testing.T) { +// Ensure that a Tx cursor can iterate over an empty bucket without error. +func TestTxCursorEmptyBucket(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") - txn, _ := db.Transaction() + txn, _ := db.Tx() c := txn.Bucket("widgets").Cursor() k, v := c.First() assert.Nil(t, k) @@ -64,14 +64,14 @@ func TestTransactionCursorEmptyBucket(t *testing.T) { }) } -// Ensure that a Transaction cursor can iterate over a single root with a couple elements. -func TestTransactionCursorLeafRoot(t *testing.T) { +// Ensure that a Tx cursor can iterate over a single root with a couple elements. +func TestTxCursorLeafRoot(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") db.Put("widgets", []byte("baz"), []byte{}) db.Put("widgets", []byte("foo"), []byte{0}) db.Put("widgets", []byte("bar"), []byte{1}) - txn, _ := db.Transaction() + txn, _ := db.Tx() c := txn.Bucket("widgets").Cursor() k, v := c.First() @@ -98,14 +98,14 @@ func TestTransactionCursorLeafRoot(t *testing.T) { }) } -// Ensure that a Transaction cursor can iterate in reverse over a single root with a couple elements. -func TestTransactionCursorLeafRootReverse(t *testing.T) { +// Ensure that a Tx cursor can iterate in reverse over a single root with a couple elements. +func TestTxCursorLeafRootReverse(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") db.Put("widgets", []byte("baz"), []byte{}) db.Put("widgets", []byte("foo"), []byte{0}) db.Put("widgets", []byte("bar"), []byte{1}) - txn, _ := db.Transaction() + txn, _ := db.Tx() c := txn.Bucket("widgets").Cursor() k, v := c.Last() @@ -132,14 +132,14 @@ func TestTransactionCursorLeafRootReverse(t *testing.T) { }) } -// Ensure that a Transaction cursor can restart from the beginning. -func TestTransactionCursorRestart(t *testing.T) { +// Ensure that a Tx cursor can restart from the beginning. +func TestTxCursorRestart(t *testing.T) { withOpenDB(func(db *DB, path string) { db.CreateBucket("widgets") db.Put("widgets", []byte("bar"), []byte{}) db.Put("widgets", []byte("foo"), []byte{}) - txn, _ := db.Transaction() + txn, _ := db.Tx() c := txn.Bucket("widgets").Cursor() k, _ := c.First() @@ -158,13 +158,13 @@ func TestTransactionCursorRestart(t *testing.T) { }) } -// Ensure that a transaction can iterate over all elements in a bucket. -func TestTransactionCursorIterate(t *testing.T) { +// Ensure that a Tx can iterate over all elements in a bucket. +func TestTxCursorIterate(t *testing.T) { f := func(items testdata) bool { withOpenDB(func(db *DB, path string) { // Bulk insert all values. db.CreateBucket("widgets") - rwtxn, _ := db.RWTransaction() + rwtxn, _ := db.RWTx() b := rwtxn.Bucket("widgets") for _, item := range items { assert.NoError(t, b.Put(item.Key, item.Value)) @@ -176,7 +176,7 @@ func TestTransactionCursorIterate(t *testing.T) { // Iterate over all items and check consistency. var index = 0 - txn, _ := db.Transaction() + txn, _ := db.Tx() c := txn.Bucket("widgets").Cursor() for k, v := c.First(); k != nil && index < len(items); k, v = c.Next() { assert.Equal(t, k, items[index].Key) @@ -196,12 +196,12 @@ func TestTransactionCursorIterate(t *testing.T) { } // Ensure that a transaction can iterate over all elements in a bucket in reverse. -func TestTransactionCursorIterateReverse(t *testing.T) { +func TestTxCursorIterateReverse(t *testing.T) { f := func(items testdata) bool { withOpenDB(func(db *DB, path string) { // Bulk insert all values. db.CreateBucket("widgets") - rwtxn, _ := db.RWTransaction() + rwtxn, _ := db.RWTx() b := rwtxn.Bucket("widgets") for _, item := range items { assert.NoError(t, b.Put(item.Key, item.Value)) @@ -213,7 +213,7 @@ func TestTransactionCursorIterateReverse(t *testing.T) { // Iterate over all items and check consistency. var index = 0 - txn, _ := db.Transaction() + txn, _ := db.Tx() c := txn.Bucket("widgets").Cursor() for k, v := c.Last(); k != nil && index < len(items); k, v = c.Prev() { assert.Equal(t, k, items[index].Key) @@ -233,14 +233,14 @@ func TestTransactionCursorIterateReverse(t *testing.T) { } // Benchmark the performance iterating over a cursor. -func BenchmarkTransactionCursor(b *testing.B) { +func BenchmarkTxCursor(b *testing.B) { indexes := rand.Perm(b.N) value := []byte(strings.Repeat("0", 64)) withOpenDB(func(db *DB, path string) { // Write data to bucket. db.CreateBucket("widgets") - db.Do(func(txn *RWTransaction) error { + db.Do(func(txn *RWTx) error { bucket := txn.Bucket("widgets") for i := 0; i < b.N; i++ { bucket.Put([]byte(strconv.Itoa(indexes[i])), value) @@ -250,7 +250,7 @@ func BenchmarkTransactionCursor(b *testing.B) { b.ResetTimer() // Iterate over bucket using cursor. - db.With(func(txn *Transaction) error { + db.With(func(txn *Tx) error { count := 0 c := txn.Bucket("widgets").Cursor() for k, _ := c.First(); k != nil; k, _ = c.Next() {