24a2b57e29
the motivation for this commit is long and detailed and has been documented externally here: https://gist.github.com/mschoch/5cc5c9cf4669a5fe8512cb7770d3c1a2 the core of the changes are: 1. recognize that collector/searcher need only a fixed number of DocumentMatch instances, and this number can be determined from the structure of the query, not the size of the data 2. knowing this, instances can be allocated in bulk, up front and they can be reused without locking (since all search operations take place in a single goroutine 3. combined with previous commits which enabled reuse of the IndexInternalID []byte, this allows for no allocation/copy of these bytes as well (by using DocumentMatch Reset() method when returning entries to the pool
71 lines
2.5 KiB
Go
71 lines
2.5 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
|
|
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
|
|
// except in compliance with the License. You may obtain a copy of the License at
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
// Unless required by applicable law or agreed to in writing, software distributed under the
|
|
// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
|
|
// either express or implied. See the License for the specific language governing permissions
|
|
// and limitations under the License.
|
|
|
|
package search
|
|
|
|
// DocumentMatchPoolTooSmall is a callback function that can be executed
|
|
// when the DocumentMatchPool does not have sufficient capacity
|
|
// By default we just perform just-in-time allocation, but you could log
|
|
// a message, or panic, etc.
|
|
type DocumentMatchPoolTooSmall func(p *DocumentMatchPool) *DocumentMatch
|
|
|
|
// DocumentMatchPool manages use/re-use of DocumentMatch instances
|
|
// it pre-allocates space from a single large block with the expected
|
|
// number of instances. It is not thread-safe as currently all
|
|
// aspects of search take place in a single goroutine.
|
|
type DocumentMatchPool struct {
|
|
avail DocumentMatchCollection
|
|
TooSmall DocumentMatchPoolTooSmall
|
|
}
|
|
|
|
func defaultDocumentMatchPoolTooSmall(p *DocumentMatchPool) *DocumentMatch {
|
|
return &DocumentMatch{}
|
|
}
|
|
|
|
// NewDocumentMatchPool will build a DocumentMatchPool with memory
|
|
// pre-allocated to accomodate the requested number of DocumentMatch
|
|
// instances
|
|
func NewDocumentMatchPool(size int) *DocumentMatchPool {
|
|
avail := make(DocumentMatchCollection, 0, size)
|
|
// pre-allocate the expected number of instances
|
|
startBlock := make([]DocumentMatch, size)
|
|
// make these initial instances available
|
|
for i := range startBlock {
|
|
avail = append(avail, &startBlock[i])
|
|
}
|
|
return &DocumentMatchPool{
|
|
avail: avail,
|
|
TooSmall: defaultDocumentMatchPoolTooSmall,
|
|
}
|
|
}
|
|
|
|
// Get returns an available DocumentMatch from the pool
|
|
// if the pool was not allocated with sufficient size, an allocation will
|
|
// occur to satisfy this request. As a side-effect this will grow the size
|
|
// of the pool.
|
|
func (p *DocumentMatchPool) Get() *DocumentMatch {
|
|
var rv *DocumentMatch
|
|
if len(p.avail) > 0 {
|
|
rv, p.avail = p.avail[len(p.avail)-1], p.avail[:len(p.avail)-1]
|
|
} else {
|
|
rv = p.TooSmall(p)
|
|
}
|
|
return rv
|
|
}
|
|
|
|
// Put returns a DocumentMatch to the pool
|
|
func (p *DocumentMatchPool) Put(d *DocumentMatch) {
|
|
if d == nil {
|
|
return
|
|
}
|
|
// reset DocumentMatch before returning it to available pool
|
|
d.Reset()
|
|
p.avail = append(p.avail, d)
|
|
}
|