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https://codeberg.org/forgejo/forgejo
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86e2789960
* update github.com/PuerkitoBio/goquery * update github.com/alecthomas/chroma * update github.com/blevesearch/bleve/v2 * update github.com/caddyserver/certmagic * update github.com/go-enry/go-enry/v2 * update github.com/go-git/go-billy/v5 * update github.com/go-git/go-git/v5 * update github.com/go-redis/redis/v8 * update github.com/go-testfixtures/testfixtures/v3 * update github.com/jaytaylor/html2text * update github.com/json-iterator/go * update github.com/klauspost/compress * update github.com/markbates/goth * update github.com/mattn/go-isatty * update github.com/mholt/archiver/v3 * update github.com/microcosm-cc/bluemonday * update github.com/minio/minio-go/v7 * update github.com/prometheus/client_golang * update github.com/unrolled/render * update github.com/xanzy/go-gitlab * update github.com/yuin/goldmark * update github.com/yuin/goldmark-highlighting Co-authored-by: techknowlogick <techknowlogick@gitea.io>
723 lines
19 KiB
Go
Vendored
723 lines
19 KiB
Go
Vendored
package bbolt
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import (
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"fmt"
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"io"
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"os"
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"sort"
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"strings"
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"time"
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"unsafe"
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)
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// txid represents the internal transaction identifier.
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type txid uint64
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// Tx represents a read-only or read/write transaction on the database.
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// Read-only transactions can be used for retrieving values for keys and creating cursors.
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// Read/write transactions can create and remove buckets and create and remove keys.
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//
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// IMPORTANT: You must commit or rollback transactions when you are done with
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// them. Pages can not be reclaimed by the writer until no more transactions
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// are using them. A long running read transaction can cause the database to
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// quickly grow.
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type Tx struct {
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writable bool
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managed bool
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db *DB
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meta *meta
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root Bucket
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pages map[pgid]*page
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stats TxStats
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commitHandlers []func()
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// WriteFlag specifies the flag for write-related methods like WriteTo().
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// Tx opens the database file with the specified flag to copy the data.
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//
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// By default, the flag is unset, which works well for mostly in-memory
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// workloads. For databases that are much larger than available RAM,
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// set the flag to syscall.O_DIRECT to avoid trashing the page cache.
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WriteFlag int
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}
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// init initializes the transaction.
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func (tx *Tx) init(db *DB) {
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tx.db = db
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tx.pages = nil
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// Copy the meta page since it can be changed by the writer.
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tx.meta = &meta{}
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db.meta().copy(tx.meta)
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// Copy over the root bucket.
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tx.root = newBucket(tx)
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tx.root.bucket = &bucket{}
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*tx.root.bucket = tx.meta.root
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// Increment the transaction id and add a page cache for writable transactions.
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if tx.writable {
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tx.pages = make(map[pgid]*page)
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tx.meta.txid += txid(1)
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}
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}
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// ID returns the transaction id.
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func (tx *Tx) ID() int {
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return int(tx.meta.txid)
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}
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// DB returns a reference to the database that created the transaction.
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func (tx *Tx) DB() *DB {
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return tx.db
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}
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// Size returns current database size in bytes as seen by this transaction.
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func (tx *Tx) Size() int64 {
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return int64(tx.meta.pgid) * int64(tx.db.pageSize)
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}
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// Writable returns whether the transaction can perform write operations.
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func (tx *Tx) Writable() bool {
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return tx.writable
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}
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// Cursor creates a cursor associated with the root bucket.
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// All items in the cursor will return a nil value because all root bucket keys point to buckets.
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// The cursor is only valid as long as the transaction is open.
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// Do not use a cursor after the transaction is closed.
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func (tx *Tx) Cursor() *Cursor {
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return tx.root.Cursor()
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}
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// Stats retrieves a copy of the current transaction statistics.
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func (tx *Tx) Stats() TxStats {
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return tx.stats
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}
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// Bucket retrieves a bucket by name.
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// Returns nil if the bucket does not exist.
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// The bucket instance is only valid for the lifetime of the transaction.
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func (tx *Tx) Bucket(name []byte) *Bucket {
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return tx.root.Bucket(name)
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}
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// CreateBucket creates a new bucket.
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// Returns an error if the bucket already exists, if the bucket name is blank, or if the bucket name is too long.
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// The bucket instance is only valid for the lifetime of the transaction.
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func (tx *Tx) CreateBucket(name []byte) (*Bucket, error) {
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return tx.root.CreateBucket(name)
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}
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// CreateBucketIfNotExists creates a new bucket if it doesn't already exist.
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// Returns an error if the bucket name is blank, or if the bucket name is too long.
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// The bucket instance is only valid for the lifetime of the transaction.
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func (tx *Tx) CreateBucketIfNotExists(name []byte) (*Bucket, error) {
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return tx.root.CreateBucketIfNotExists(name)
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}
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// DeleteBucket deletes a bucket.
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// Returns an error if the bucket cannot be found or if the key represents a non-bucket value.
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func (tx *Tx) DeleteBucket(name []byte) error {
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return tx.root.DeleteBucket(name)
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}
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// ForEach executes a function for each bucket in the root.
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// If the provided function returns an error then the iteration is stopped and
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// the error is returned to the caller.
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func (tx *Tx) ForEach(fn func(name []byte, b *Bucket) error) error {
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return tx.root.ForEach(func(k, v []byte) error {
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return fn(k, tx.root.Bucket(k))
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})
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}
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// OnCommit adds a handler function to be executed after the transaction successfully commits.
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func (tx *Tx) OnCommit(fn func()) {
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tx.commitHandlers = append(tx.commitHandlers, fn)
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}
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// Commit writes all changes to disk and updates the meta page.
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// Returns an error if a disk write error occurs, or if Commit is
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// called on a read-only transaction.
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func (tx *Tx) Commit() error {
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_assert(!tx.managed, "managed tx commit not allowed")
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if tx.db == nil {
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return ErrTxClosed
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} else if !tx.writable {
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return ErrTxNotWritable
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}
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// TODO(benbjohnson): Use vectorized I/O to write out dirty pages.
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// Rebalance nodes which have had deletions.
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var startTime = time.Now()
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tx.root.rebalance()
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if tx.stats.Rebalance > 0 {
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tx.stats.RebalanceTime += time.Since(startTime)
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}
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// spill data onto dirty pages.
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startTime = time.Now()
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if err := tx.root.spill(); err != nil {
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tx.rollback()
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return err
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}
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tx.stats.SpillTime += time.Since(startTime)
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// Free the old root bucket.
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tx.meta.root.root = tx.root.root
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// Free the old freelist because commit writes out a fresh freelist.
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if tx.meta.freelist != pgidNoFreelist {
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tx.db.freelist.free(tx.meta.txid, tx.db.page(tx.meta.freelist))
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}
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if !tx.db.NoFreelistSync {
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err := tx.commitFreelist()
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if err != nil {
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return err
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}
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} else {
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tx.meta.freelist = pgidNoFreelist
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}
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// Write dirty pages to disk.
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startTime = time.Now()
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if err := tx.write(); err != nil {
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tx.rollback()
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return err
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}
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// If strict mode is enabled then perform a consistency check.
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if tx.db.StrictMode {
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ch := tx.Check()
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var errs []string
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for {
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err, ok := <-ch
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if !ok {
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break
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}
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errs = append(errs, err.Error())
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}
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if len(errs) > 0 {
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panic("check fail: " + strings.Join(errs, "\n"))
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}
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}
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// Write meta to disk.
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if err := tx.writeMeta(); err != nil {
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tx.rollback()
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return err
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}
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tx.stats.WriteTime += time.Since(startTime)
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// Finalize the transaction.
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tx.close()
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// Execute commit handlers now that the locks have been removed.
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for _, fn := range tx.commitHandlers {
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fn()
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}
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return nil
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}
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func (tx *Tx) commitFreelist() error {
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// Allocate new pages for the new free list. This will overestimate
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// the size of the freelist but not underestimate the size (which would be bad).
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opgid := tx.meta.pgid
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p, err := tx.allocate((tx.db.freelist.size() / tx.db.pageSize) + 1)
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if err != nil {
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tx.rollback()
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return err
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}
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if err := tx.db.freelist.write(p); err != nil {
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tx.rollback()
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return err
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}
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tx.meta.freelist = p.id
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// If the high water mark has moved up then attempt to grow the database.
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if tx.meta.pgid > opgid {
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if err := tx.db.grow(int(tx.meta.pgid+1) * tx.db.pageSize); err != nil {
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tx.rollback()
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return err
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}
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}
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return nil
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}
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// Rollback closes the transaction and ignores all previous updates. Read-only
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// transactions must be rolled back and not committed.
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func (tx *Tx) Rollback() error {
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_assert(!tx.managed, "managed tx rollback not allowed")
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if tx.db == nil {
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return ErrTxClosed
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}
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tx.nonPhysicalRollback()
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return nil
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}
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// nonPhysicalRollback is called when user calls Rollback directly, in this case we do not need to reload the free pages from disk.
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func (tx *Tx) nonPhysicalRollback() {
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if tx.db == nil {
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return
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}
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if tx.writable {
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tx.db.freelist.rollback(tx.meta.txid)
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}
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tx.close()
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}
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// rollback needs to reload the free pages from disk in case some system error happens like fsync error.
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func (tx *Tx) rollback() {
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if tx.db == nil {
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return
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}
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if tx.writable {
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tx.db.freelist.rollback(tx.meta.txid)
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if !tx.db.hasSyncedFreelist() {
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// Reconstruct free page list by scanning the DB to get the whole free page list.
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// Note: scaning the whole db is heavy if your db size is large in NoSyncFreeList mode.
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tx.db.freelist.noSyncReload(tx.db.freepages())
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} else {
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// Read free page list from freelist page.
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tx.db.freelist.reload(tx.db.page(tx.db.meta().freelist))
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}
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}
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tx.close()
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}
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func (tx *Tx) close() {
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if tx.db == nil {
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return
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}
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if tx.writable {
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// Grab freelist stats.
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var freelistFreeN = tx.db.freelist.free_count()
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var freelistPendingN = tx.db.freelist.pending_count()
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var freelistAlloc = tx.db.freelist.size()
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// Remove transaction ref & writer lock.
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tx.db.rwtx = nil
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tx.db.rwlock.Unlock()
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// Merge statistics.
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tx.db.statlock.Lock()
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tx.db.stats.FreePageN = freelistFreeN
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tx.db.stats.PendingPageN = freelistPendingN
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tx.db.stats.FreeAlloc = (freelistFreeN + freelistPendingN) * tx.db.pageSize
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tx.db.stats.FreelistInuse = freelistAlloc
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tx.db.stats.TxStats.add(&tx.stats)
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tx.db.statlock.Unlock()
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} else {
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tx.db.removeTx(tx)
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}
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// Clear all references.
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tx.db = nil
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tx.meta = nil
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tx.root = Bucket{tx: tx}
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tx.pages = nil
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}
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// Copy writes the entire database to a writer.
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// This function exists for backwards compatibility.
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//
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// Deprecated; Use WriteTo() instead.
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func (tx *Tx) Copy(w io.Writer) error {
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_, err := tx.WriteTo(w)
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return err
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}
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// WriteTo writes the entire database to a writer.
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// If err == nil then exactly tx.Size() bytes will be written into the writer.
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func (tx *Tx) WriteTo(w io.Writer) (n int64, err error) {
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// Attempt to open reader with WriteFlag
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f, err := tx.db.openFile(tx.db.path, os.O_RDONLY|tx.WriteFlag, 0)
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if err != nil {
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return 0, err
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}
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defer func() {
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if cerr := f.Close(); err == nil {
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err = cerr
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}
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}()
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// Generate a meta page. We use the same page data for both meta pages.
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buf := make([]byte, tx.db.pageSize)
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page := (*page)(unsafe.Pointer(&buf[0]))
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page.flags = metaPageFlag
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*page.meta() = *tx.meta
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// Write meta 0.
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page.id = 0
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page.meta().checksum = page.meta().sum64()
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nn, err := w.Write(buf)
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n += int64(nn)
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if err != nil {
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return n, fmt.Errorf("meta 0 copy: %s", err)
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}
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// Write meta 1 with a lower transaction id.
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page.id = 1
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page.meta().txid -= 1
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page.meta().checksum = page.meta().sum64()
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nn, err = w.Write(buf)
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n += int64(nn)
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if err != nil {
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return n, fmt.Errorf("meta 1 copy: %s", err)
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}
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// Move past the meta pages in the file.
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if _, err := f.Seek(int64(tx.db.pageSize*2), io.SeekStart); err != nil {
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return n, fmt.Errorf("seek: %s", err)
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}
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// Copy data pages.
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wn, err := io.CopyN(w, f, tx.Size()-int64(tx.db.pageSize*2))
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n += wn
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if err != nil {
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return n, err
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}
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return n, nil
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}
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// CopyFile copies the entire database to file at the given path.
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// A reader transaction is maintained during the copy so it is safe to continue
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// using the database while a copy is in progress.
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func (tx *Tx) CopyFile(path string, mode os.FileMode) error {
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f, err := tx.db.openFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, mode)
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if err != nil {
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return err
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}
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_, err = tx.WriteTo(f)
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if err != nil {
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_ = f.Close()
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return err
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}
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return f.Close()
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}
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// Check performs several consistency checks on the database for this transaction.
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// An error is returned if any inconsistency is found.
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//
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// It can be safely run concurrently on a writable transaction. However, this
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// incurs a high cost for large databases and databases with a lot of subbuckets
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// because of caching. This overhead can be removed if running on a read-only
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// transaction, however, it is not safe to execute other writer transactions at
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// the same time.
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func (tx *Tx) Check() <-chan error {
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ch := make(chan error)
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go tx.check(ch)
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return ch
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}
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func (tx *Tx) check(ch chan error) {
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// Force loading free list if opened in ReadOnly mode.
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tx.db.loadFreelist()
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// Check if any pages are double freed.
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freed := make(map[pgid]bool)
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all := make([]pgid, tx.db.freelist.count())
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tx.db.freelist.copyall(all)
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for _, id := range all {
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if freed[id] {
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ch <- fmt.Errorf("page %d: already freed", id)
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}
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freed[id] = true
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}
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|
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// Track every reachable page.
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reachable := make(map[pgid]*page)
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reachable[0] = tx.page(0) // meta0
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reachable[1] = tx.page(1) // meta1
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if tx.meta.freelist != pgidNoFreelist {
|
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for i := uint32(0); i <= tx.page(tx.meta.freelist).overflow; i++ {
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reachable[tx.meta.freelist+pgid(i)] = tx.page(tx.meta.freelist)
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}
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}
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|
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// Recursively check buckets.
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tx.checkBucket(&tx.root, reachable, freed, ch)
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|
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// Ensure all pages below high water mark are either reachable or freed.
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for i := pgid(0); i < tx.meta.pgid; i++ {
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_, isReachable := reachable[i]
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if !isReachable && !freed[i] {
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ch <- fmt.Errorf("page %d: unreachable unfreed", int(i))
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}
|
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}
|
|
|
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// Close the channel to signal completion.
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close(ch)
|
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}
|
|
|
|
func (tx *Tx) checkBucket(b *Bucket, reachable map[pgid]*page, freed map[pgid]bool, ch chan error) {
|
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// Ignore inline buckets.
|
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if b.root == 0 {
|
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return
|
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}
|
|
|
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// Check every page used by this bucket.
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b.tx.forEachPage(b.root, 0, func(p *page, _ int) {
|
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if p.id > tx.meta.pgid {
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ch <- fmt.Errorf("page %d: out of bounds: %d", int(p.id), int(b.tx.meta.pgid))
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}
|
|
|
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// Ensure each page is only referenced once.
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for i := pgid(0); i <= pgid(p.overflow); i++ {
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var id = p.id + i
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if _, ok := reachable[id]; ok {
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ch <- fmt.Errorf("page %d: multiple references", int(id))
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}
|
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reachable[id] = p
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}
|
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|
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// We should only encounter un-freed leaf and branch pages.
|
|
if freed[p.id] {
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ch <- fmt.Errorf("page %d: reachable freed", int(p.id))
|
|
} else if (p.flags&branchPageFlag) == 0 && (p.flags&leafPageFlag) == 0 {
|
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ch <- fmt.Errorf("page %d: invalid type: %s", int(p.id), p.typ())
|
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}
|
|
})
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|
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// Check each bucket within this bucket.
|
|
_ = b.ForEach(func(k, v []byte) error {
|
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if child := b.Bucket(k); child != nil {
|
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tx.checkBucket(child, reachable, freed, ch)
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}
|
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return nil
|
|
})
|
|
}
|
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|
|
// allocate returns a contiguous block of memory starting at a given page.
|
|
func (tx *Tx) allocate(count int) (*page, error) {
|
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p, err := tx.db.allocate(tx.meta.txid, count)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Save to our page cache.
|
|
tx.pages[p.id] = p
|
|
|
|
// Update statistics.
|
|
tx.stats.PageCount += count
|
|
tx.stats.PageAlloc += count * tx.db.pageSize
|
|
|
|
return p, nil
|
|
}
|
|
|
|
// write writes any dirty pages to disk.
|
|
func (tx *Tx) write() error {
|
|
// Sort pages by id.
|
|
pages := make(pages, 0, len(tx.pages))
|
|
for _, p := range tx.pages {
|
|
pages = append(pages, p)
|
|
}
|
|
// Clear out page cache early.
|
|
tx.pages = make(map[pgid]*page)
|
|
sort.Sort(pages)
|
|
|
|
// Write pages to disk in order.
|
|
for _, p := range pages {
|
|
rem := (uint64(p.overflow) + 1) * uint64(tx.db.pageSize)
|
|
offset := int64(p.id) * int64(tx.db.pageSize)
|
|
var written uintptr
|
|
|
|
// Write out page in "max allocation" sized chunks.
|
|
for {
|
|
sz := rem
|
|
if sz > maxAllocSize-1 {
|
|
sz = maxAllocSize - 1
|
|
}
|
|
buf := unsafeByteSlice(unsafe.Pointer(p), written, 0, int(sz))
|
|
|
|
if _, err := tx.db.ops.writeAt(buf, offset); err != nil {
|
|
return err
|
|
}
|
|
|
|
// Update statistics.
|
|
tx.stats.Write++
|
|
|
|
// Exit inner for loop if we've written all the chunks.
|
|
rem -= sz
|
|
if rem == 0 {
|
|
break
|
|
}
|
|
|
|
// Otherwise move offset forward and move pointer to next chunk.
|
|
offset += int64(sz)
|
|
written += uintptr(sz)
|
|
}
|
|
}
|
|
|
|
// Ignore file sync if flag is set on DB.
|
|
if !tx.db.NoSync || IgnoreNoSync {
|
|
if err := fdatasync(tx.db); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
// Put small pages back to page pool.
|
|
for _, p := range pages {
|
|
// Ignore page sizes over 1 page.
|
|
// These are allocated using make() instead of the page pool.
|
|
if int(p.overflow) != 0 {
|
|
continue
|
|
}
|
|
|
|
buf := unsafeByteSlice(unsafe.Pointer(p), 0, 0, tx.db.pageSize)
|
|
|
|
// See https://go.googlesource.com/go/+/f03c9202c43e0abb130669852082117ca50aa9b1
|
|
for i := range buf {
|
|
buf[i] = 0
|
|
}
|
|
tx.db.pagePool.Put(buf)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// writeMeta writes the meta to the disk.
|
|
func (tx *Tx) writeMeta() error {
|
|
// Create a temporary buffer for the meta page.
|
|
buf := make([]byte, tx.db.pageSize)
|
|
p := tx.db.pageInBuffer(buf, 0)
|
|
tx.meta.write(p)
|
|
|
|
// Write the meta page to file.
|
|
if _, err := tx.db.ops.writeAt(buf, int64(p.id)*int64(tx.db.pageSize)); err != nil {
|
|
return err
|
|
}
|
|
if !tx.db.NoSync || IgnoreNoSync {
|
|
if err := fdatasync(tx.db); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
// Update statistics.
|
|
tx.stats.Write++
|
|
|
|
return nil
|
|
}
|
|
|
|
// page returns a reference to the page with a given id.
|
|
// If page has been written to then a temporary buffered page is returned.
|
|
func (tx *Tx) page(id pgid) *page {
|
|
// Check the dirty pages first.
|
|
if tx.pages != nil {
|
|
if p, ok := tx.pages[id]; ok {
|
|
return p
|
|
}
|
|
}
|
|
|
|
// Otherwise return directly from the mmap.
|
|
return tx.db.page(id)
|
|
}
|
|
|
|
// forEachPage iterates over every page within a given page and executes a function.
|
|
func (tx *Tx) forEachPage(pgid pgid, depth int, fn func(*page, int)) {
|
|
p := tx.page(pgid)
|
|
|
|
// Execute function.
|
|
fn(p, depth)
|
|
|
|
// Recursively loop over children.
|
|
if (p.flags & branchPageFlag) != 0 {
|
|
for i := 0; i < int(p.count); i++ {
|
|
elem := p.branchPageElement(uint16(i))
|
|
tx.forEachPage(elem.pgid, depth+1, fn)
|
|
}
|
|
}
|
|
}
|
|
|
|
// Page returns page information for a given page number.
|
|
// This is only safe for concurrent use when used by a writable transaction.
|
|
func (tx *Tx) Page(id int) (*PageInfo, error) {
|
|
if tx.db == nil {
|
|
return nil, ErrTxClosed
|
|
} else if pgid(id) >= tx.meta.pgid {
|
|
return nil, nil
|
|
}
|
|
|
|
// Build the page info.
|
|
p := tx.db.page(pgid(id))
|
|
info := &PageInfo{
|
|
ID: id,
|
|
Count: int(p.count),
|
|
OverflowCount: int(p.overflow),
|
|
}
|
|
|
|
// Determine the type (or if it's free).
|
|
if tx.db.freelist.freed(pgid(id)) {
|
|
info.Type = "free"
|
|
} else {
|
|
info.Type = p.typ()
|
|
}
|
|
|
|
return info, nil
|
|
}
|
|
|
|
// TxStats represents statistics about the actions performed by the transaction.
|
|
type TxStats struct {
|
|
// Page statistics.
|
|
PageCount int // number of page allocations
|
|
PageAlloc int // total bytes allocated
|
|
|
|
// Cursor statistics.
|
|
CursorCount int // number of cursors created
|
|
|
|
// Node statistics
|
|
NodeCount int // number of node allocations
|
|
NodeDeref int // number of node dereferences
|
|
|
|
// Rebalance statistics.
|
|
Rebalance int // number of node rebalances
|
|
RebalanceTime time.Duration // total time spent rebalancing
|
|
|
|
// Split/Spill statistics.
|
|
Split int // number of nodes split
|
|
Spill int // number of nodes spilled
|
|
SpillTime time.Duration // total time spent spilling
|
|
|
|
// Write statistics.
|
|
Write int // number of writes performed
|
|
WriteTime time.Duration // total time spent writing to disk
|
|
}
|
|
|
|
func (s *TxStats) add(other *TxStats) {
|
|
s.PageCount += other.PageCount
|
|
s.PageAlloc += other.PageAlloc
|
|
s.CursorCount += other.CursorCount
|
|
s.NodeCount += other.NodeCount
|
|
s.NodeDeref += other.NodeDeref
|
|
s.Rebalance += other.Rebalance
|
|
s.RebalanceTime += other.RebalanceTime
|
|
s.Split += other.Split
|
|
s.Spill += other.Spill
|
|
s.SpillTime += other.SpillTime
|
|
s.Write += other.Write
|
|
s.WriteTime += other.WriteTime
|
|
}
|
|
|
|
// Sub calculates and returns the difference between two sets of transaction stats.
|
|
// This is useful when obtaining stats at two different points and time and
|
|
// you need the performance counters that occurred within that time span.
|
|
func (s *TxStats) Sub(other *TxStats) TxStats {
|
|
var diff TxStats
|
|
diff.PageCount = s.PageCount - other.PageCount
|
|
diff.PageAlloc = s.PageAlloc - other.PageAlloc
|
|
diff.CursorCount = s.CursorCount - other.CursorCount
|
|
diff.NodeCount = s.NodeCount - other.NodeCount
|
|
diff.NodeDeref = s.NodeDeref - other.NodeDeref
|
|
diff.Rebalance = s.Rebalance - other.Rebalance
|
|
diff.RebalanceTime = s.RebalanceTime - other.RebalanceTime
|
|
diff.Split = s.Split - other.Split
|
|
diff.Spill = s.Spill - other.Spill
|
|
diff.SpillTime = s.SpillTime - other.SpillTime
|
|
diff.Write = s.Write - other.Write
|
|
diff.WriteTime = s.WriteTime - other.WriteTime
|
|
return diff
|
|
}
|