Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

index/scorch/segment_plugin.go

@@ -0,0 +1,144 @@
+//  Copyright (c) 2019 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 scorch
+
+import (
+	"fmt"
+
+	"github.com/RoaringBitmap/roaring/v2"
+	"github.com/blevesearch/bleve/v2/geo"
+	index "github.com/blevesearch/bleve_index_api"
+	segment "github.com/blevesearch/scorch_segment_api/v2"
+
+	zapv11 "github.com/blevesearch/zapx/v11"
+	zapv12 "github.com/blevesearch/zapx/v12"
+	zapv13 "github.com/blevesearch/zapx/v13"
+	zapv14 "github.com/blevesearch/zapx/v14"
+	zapv15 "github.com/blevesearch/zapx/v15"
+	zapv16 "github.com/blevesearch/zapx/v16"
+)
+
+// SegmentPlugin represents the essential functions required by a package to plug in
+// it's segment implementation
+type SegmentPlugin interface {
+
+	// Type is the name for this segment plugin
+	Type() string
+
+	// Version is a numeric value identifying a specific version of this type.
+	// When incompatible changes are made to a particular type of plugin, the
+	// version must be incremented.
+	Version() uint32
+
+	// New takes a set of Documents and turns them into a new Segment
+	New(results []index.Document) (segment.Segment, uint64, error)
+
+	// Open attempts to open the file at the specified path and
+	// return the corresponding Segment
+	Open(path string) (segment.Segment, error)
+
+	// Merge takes a set of Segments, and creates a new segment on disk at
+	// the specified path.
+	// Drops is a set of bitmaps (one for each segment) indicating which
+	// documents can be dropped from the segments during the merge.
+	// If the closeCh channel is closed, Merge will cease doing work at
+	// the next opportunity, and return an error (closed).
+	// StatsReporter can optionally be provided, in which case progress
+	// made during the merge is reported while operation continues.
+	// Returns:
+	// A slice of new document numbers (one for each input segment),
+	// this allows the caller to know a particular document's new
+	// document number in the newly merged segment.
+	// The number of bytes written to the new segment file.
+	// An error, if any occurred.
+	Merge(segments []segment.Segment, drops []*roaring.Bitmap, path string,
+		closeCh chan struct{}, s segment.StatsReporter) (
+		[][]uint64, uint64, error)
+}
+
+var supportedSegmentPlugins map[string]map[uint32]SegmentPlugin
+var defaultSegmentPlugin SegmentPlugin
+
+func init() {
+	ResetSegmentPlugins()
+	RegisterSegmentPlugin(&zapv16.ZapPlugin{}, true)
+	RegisterSegmentPlugin(&zapv15.ZapPlugin{}, false)
+	RegisterSegmentPlugin(&zapv14.ZapPlugin{}, false)
+	RegisterSegmentPlugin(&zapv13.ZapPlugin{}, false)
+	RegisterSegmentPlugin(&zapv12.ZapPlugin{}, false)
+	RegisterSegmentPlugin(&zapv11.ZapPlugin{}, false)
+}
+
+func ResetSegmentPlugins() {
+	supportedSegmentPlugins = map[string]map[uint32]SegmentPlugin{}
+}
+
+func RegisterSegmentPlugin(plugin SegmentPlugin, makeDefault bool) {
+	if _, ok := supportedSegmentPlugins[plugin.Type()]; !ok {
+		supportedSegmentPlugins[plugin.Type()] = map[uint32]SegmentPlugin{}
+	}
+	supportedSegmentPlugins[plugin.Type()][plugin.Version()] = plugin
+	if makeDefault {
+		defaultSegmentPlugin = plugin
+	}
+}
+
+func SupportedSegmentTypes() (rv []string) {
+	for k := range supportedSegmentPlugins {
+		rv = append(rv, k)
+	}
+	return
+}
+
+func SupportedSegmentTypeVersions(typ string) (rv []uint32) {
+	for k := range supportedSegmentPlugins[typ] {
+		rv = append(rv, k)
+	}
+	return rv
+}
+
+func chooseSegmentPlugin(forcedSegmentType string,
+	forcedSegmentVersion uint32) (SegmentPlugin, error) {
+	if versions, ok := supportedSegmentPlugins[forcedSegmentType]; ok {
+		if segPlugin, ok := versions[uint32(forcedSegmentVersion)]; ok {
+			return segPlugin, nil
+		}
+		return nil, fmt.Errorf(
+			"unsupported version %d for segment type: %s, supported: %v",
+			forcedSegmentVersion, forcedSegmentType,
+			SupportedSegmentTypeVersions(forcedSegmentType))
+	}
+	return nil, fmt.Errorf("unsupported segment type: %s, supported: %v",
+		forcedSegmentType, SupportedSegmentTypes())
+}
+
+func (s *Scorch) loadSegmentPlugin(forcedSegmentType string,
+	forcedSegmentVersion uint32) error {
+	segPlugin, err := chooseSegmentPlugin(forcedSegmentType,
+		forcedSegmentVersion)
+	if err != nil {
+		return err
+	}
+	s.segPlugin = segPlugin
+	return nil
+}
+
+func (s *Scorch) loadSpatialAnalyzerPlugin(typ string) error {
+	s.spatialPlugin = geo.GetSpatialAnalyzerPlugin(typ)
+	if s.spatialPlugin == nil {
+		return fmt.Errorf("unsupported spatial plugin type: %s", typ)
+	}
+	return nil
+}