blob: 47e16b90a1317ffb2eec82032afcc6826a01ab96 [file] [log] [blame]
// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package symbol
import (
"sort"
"golang.org/x/mod/semver"
"golang.org/x/pkgsite/internal"
)
// IntroducedHistory returns a map of the first version when a symbol name is
// added to the API, to the symbol name, to the UnitSymbol struct. The
// UnitSymbol.Children field will always be empty, as children names are also
// tracked.
func IntroducedHistory(versionToNameToUnitSymbol map[string]map[string]*internal.UnitSymbol) (
outVersionToNameToUnitSymbol map[string]map[string]*internal.UnitSymbol) {
// Create an array of the versions in versionToNameToUnitSymbol, sorted by
// increasing semver.
var orderdVersions []string
for v := range versionToNameToUnitSymbol {
orderdVersions = append(orderdVersions, v)
}
sort.Slice(orderdVersions, func(i, j int) bool {
return semver.Compare(orderdVersions[i], orderdVersions[j]) == -1
})
// Generate a map of the symbol names for each build context, and the first
// version when that symbol name was found in the package.
buildToNameToVersion := map[internal.BuildContext]map[string]string{}
for _, v := range orderdVersions {
nameToUnitSymbol := versionToNameToUnitSymbol[v]
for _, us := range nameToUnitSymbol {
for _, build := range us.BuildContexts() {
if _, ok := buildToNameToVersion[build]; !ok {
buildToNameToVersion[build] = map[string]string{}
}
if _, ok := buildToNameToVersion[build][us.Name]; !ok {
buildToNameToVersion[build][us.Name] = v
}
}
}
}
// Using the map of buildToNameToVersion, construct a map of
// versionToNameToUnitSymbol, where version is the first version when the
// symbol name was found in the package.
outVersionToNameToUnitSymbol = map[string]map[string]*internal.UnitSymbol{}
for build, nameToVersion := range buildToNameToVersion {
for name, version := range nameToVersion {
if _, ok := outVersionToNameToUnitSymbol[version]; !ok {
outVersionToNameToUnitSymbol[version] = map[string]*internal.UnitSymbol{}
}
us, ok := outVersionToNameToUnitSymbol[version][name]
if !ok {
us = versionToNameToUnitSymbol[version][name]
us.RemoveBuildContexts()
outVersionToNameToUnitSymbol[version][name] = us
}
us.AddBuildContext(build)
}
}
return outVersionToNameToUnitSymbol
}