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147 lines
3.3 KiB
147 lines
3.3 KiB
package redis |
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import ( |
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"context" |
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"sync" |
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"github.com/go-redis/redis/v8/internal/pool" |
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) |
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type pipelineExecer func(context.Context, []Cmder) error |
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// Pipeliner is an mechanism to realise Redis Pipeline technique. |
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// |
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// Pipelining is a technique to extremely speed up processing by packing |
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// operations to batches, send them at once to Redis and read a replies in a |
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// singe step. |
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// See https://redis.io/topics/pipelining |
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// |
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// Pay attention, that Pipeline is not a transaction, so you can get unexpected |
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// results in case of big pipelines and small read/write timeouts. |
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// Redis client has retransmission logic in case of timeouts, pipeline |
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// can be retransmitted and commands can be executed more then once. |
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// To avoid this: it is good idea to use reasonable bigger read/write timeouts |
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// depends of your batch size and/or use TxPipeline. |
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type Pipeliner interface { |
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StatefulCmdable |
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Len() int |
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Do(ctx context.Context, args ...interface{}) *Cmd |
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Process(ctx context.Context, cmd Cmder) error |
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Close() error |
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Discard() error |
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Exec(ctx context.Context) ([]Cmder, error) |
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} |
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var _ Pipeliner = (*Pipeline)(nil) |
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// Pipeline implements pipelining as described in |
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// http://redis.io/topics/pipelining. It's safe for concurrent use |
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// by multiple goroutines. |
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type Pipeline struct { |
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cmdable |
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statefulCmdable |
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ctx context.Context |
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exec pipelineExecer |
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mu sync.Mutex |
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cmds []Cmder |
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closed bool |
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} |
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func (c *Pipeline) init() { |
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c.cmdable = c.Process |
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c.statefulCmdable = c.Process |
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} |
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// Len returns the number of queued commands. |
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func (c *Pipeline) Len() int { |
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c.mu.Lock() |
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ln := len(c.cmds) |
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c.mu.Unlock() |
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return ln |
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} |
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// Do queues the custom command for later execution. |
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func (c *Pipeline) Do(ctx context.Context, args ...interface{}) *Cmd { |
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cmd := NewCmd(ctx, args...) |
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_ = c.Process(ctx, cmd) |
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return cmd |
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} |
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// Process queues the cmd for later execution. |
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func (c *Pipeline) Process(ctx context.Context, cmd Cmder) error { |
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c.mu.Lock() |
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c.cmds = append(c.cmds, cmd) |
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c.mu.Unlock() |
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return nil |
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} |
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// Close closes the pipeline, releasing any open resources. |
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func (c *Pipeline) Close() error { |
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c.mu.Lock() |
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_ = c.discard() |
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c.closed = true |
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c.mu.Unlock() |
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return nil |
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} |
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// Discard resets the pipeline and discards queued commands. |
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func (c *Pipeline) Discard() error { |
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c.mu.Lock() |
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err := c.discard() |
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c.mu.Unlock() |
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return err |
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} |
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func (c *Pipeline) discard() error { |
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if c.closed { |
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return pool.ErrClosed |
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} |
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c.cmds = c.cmds[:0] |
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return nil |
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} |
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// Exec executes all previously queued commands using one |
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// client-server roundtrip. |
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// |
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// Exec always returns list of commands and error of the first failed |
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// command if any. |
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func (c *Pipeline) Exec(ctx context.Context) ([]Cmder, error) { |
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c.mu.Lock() |
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defer c.mu.Unlock() |
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if c.closed { |
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return nil, pool.ErrClosed |
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} |
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if len(c.cmds) == 0 { |
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return nil, nil |
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} |
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cmds := c.cmds |
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c.cmds = nil |
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return cmds, c.exec(ctx, cmds) |
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} |
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func (c *Pipeline) Pipelined(ctx context.Context, fn func(Pipeliner) error) ([]Cmder, error) { |
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if err := fn(c); err != nil { |
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return nil, err |
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} |
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cmds, err := c.Exec(ctx) |
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_ = c.Close() |
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return cmds, err |
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} |
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func (c *Pipeline) Pipeline() Pipeliner { |
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return c |
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} |
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func (c *Pipeline) TxPipelined(ctx context.Context, fn func(Pipeliner) error) ([]Cmder, error) { |
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return c.Pipelined(ctx, fn) |
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} |
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func (c *Pipeline) TxPipeline() Pipeliner { |
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return c |
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}
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