internal/gcimporter: port memory reuse optimizations from Go tree

original CL was https://go.dev/cl/433037
"cmd/compile: introduce "temporary" readers for more storage reuse"

Change-Id: I8989ae45b17a84451d29c7dc95b8ab2a06b6f153
Reviewed-on: https://go-review.googlesource.com/c/tools/+/449499
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: David Chase <drchase@google.com>
This commit is contained in:
David Chase 2022-11-10 15:19:38 -05:00
parent fc702c522d
commit 06fb723d2f
2 changed files with 126 additions and 45 deletions

View File

@ -158,6 +158,17 @@ func (pr *pkgReader) newReader(k pkgbits.RelocKind, idx pkgbits.Index, marker pk
}
}
func (pr *pkgReader) tempReader(k pkgbits.RelocKind, idx pkgbits.Index, marker pkgbits.SyncMarker) *reader {
return &reader{
Decoder: pr.TempDecoder(k, idx, marker),
p: pr,
}
}
func (pr *pkgReader) retireReader(r *reader) {
pr.RetireDecoder(&r.Decoder)
}
// @@@ Positions
func (r *reader) pos() token.Pos {
@ -182,26 +193,29 @@ func (pr *pkgReader) posBaseIdx(idx pkgbits.Index) string {
return b
}
r := pr.newReader(pkgbits.RelocPosBase, idx, pkgbits.SyncPosBase)
var filename string
{
r := pr.tempReader(pkgbits.RelocPosBase, idx, pkgbits.SyncPosBase)
// Within types2, position bases have a lot more details (e.g.,
// keeping track of where //line directives appeared exactly).
//
// For go/types, we just track the file name.
// Within types2, position bases have a lot more details (e.g.,
// keeping track of where //line directives appeared exactly).
//
// For go/types, we just track the file name.
filename := r.String()
filename = r.String()
if r.Bool() { // file base
// Was: "b = token.NewTrimmedFileBase(filename, true)"
} else { // line base
pos := r.pos()
line := r.Uint()
col := r.Uint()
if r.Bool() { // file base
// Was: "b = token.NewTrimmedFileBase(filename, true)"
} else { // line base
pos := r.pos()
line := r.Uint()
col := r.Uint()
// Was: "b = token.NewLineBase(pos, filename, true, line, col)"
_, _, _ = pos, line, col
// Was: "b = token.NewLineBase(pos, filename, true, line, col)"
_, _, _ = pos, line, col
}
pr.retireReader(r)
}
b := filename
pr.posBases[idx] = b
return b
@ -307,12 +321,15 @@ func (pr *pkgReader) typIdx(info typeInfo, dict *readerDict) types.Type {
return typ
}
r := pr.newReader(pkgbits.RelocType, idx, pkgbits.SyncTypeIdx)
r.dict = dict
typ := r.doTyp()
assert(typ != nil)
var typ types.Type
{
r := pr.tempReader(pkgbits.RelocType, idx, pkgbits.SyncTypeIdx)
r.dict = dict
typ = r.doTyp()
assert(typ != nil)
pr.retireReader(r)
}
// See comment in pkgReader.typIdx explaining how this happens.
if prev := *where; prev != nil {
return prev
@ -478,12 +495,19 @@ func (r *reader) obj() (types.Object, []types.Type) {
}
func (pr *pkgReader) objIdx(idx pkgbits.Index) (*types.Package, string) {
rname := pr.newReader(pkgbits.RelocName, idx, pkgbits.SyncObject1)
objPkg, objName := rname.qualifiedIdent()
assert(objName != "")
var objPkg *types.Package
var objName string
var tag pkgbits.CodeObj
{
rname := pr.tempReader(pkgbits.RelocName, idx, pkgbits.SyncObject1)
tag := pkgbits.CodeObj(rname.Code(pkgbits.SyncCodeObj))
objPkg, objName = rname.qualifiedIdent()
assert(objName != "")
tag = pkgbits.CodeObj(rname.Code(pkgbits.SyncCodeObj))
pr.retireReader(rname)
}
if tag == pkgbits.ObjStub {
assert(objPkg == nil || objPkg == types.Unsafe)
@ -588,25 +612,28 @@ func (pr *pkgReader) objIdx(idx pkgbits.Index) (*types.Package, string) {
}
func (pr *pkgReader) objDictIdx(idx pkgbits.Index) *readerDict {
r := pr.newReader(pkgbits.RelocObjDict, idx, pkgbits.SyncObject1)
var dict readerDict
if implicits := r.Len(); implicits != 0 {
errorf("unexpected object with %v implicit type parameter(s)", implicits)
}
{
r := pr.tempReader(pkgbits.RelocObjDict, idx, pkgbits.SyncObject1)
if implicits := r.Len(); implicits != 0 {
errorf("unexpected object with %v implicit type parameter(s)", implicits)
}
dict.bounds = make([]typeInfo, r.Len())
for i := range dict.bounds {
dict.bounds[i] = r.typInfo()
}
dict.bounds = make([]typeInfo, r.Len())
for i := range dict.bounds {
dict.bounds[i] = r.typInfo()
}
dict.derived = make([]derivedInfo, r.Len())
dict.derivedTypes = make([]types.Type, len(dict.derived))
for i := range dict.derived {
dict.derived[i] = derivedInfo{r.Reloc(pkgbits.RelocType), r.Bool()}
}
dict.derived = make([]derivedInfo, r.Len())
dict.derivedTypes = make([]types.Type, len(dict.derived))
for i := range dict.derived {
dict.derived[i] = derivedInfo{r.Reloc(pkgbits.RelocType), r.Bool()}
}
pr.retireReader(r)
}
// function references follow, but reader doesn't need those
return &dict

View File

@ -52,6 +52,8 @@ type PkgDecoder struct {
// For example, section K's end positions start at elemEndsEnds[K-1]
// (or 0, if K==0) and end at elemEndsEnds[K].
elemEndsEnds [numRelocs]uint32
scratchRelocEnt []RelocEnt
}
// PkgPath returns the package path for the package
@ -165,6 +167,21 @@ func (pr *PkgDecoder) NewDecoder(k RelocKind, idx Index, marker SyncMarker) Deco
return r
}
// TempDecoder returns a Decoder for the given (section, index) pair,
// and decodes the given SyncMarker from the element bitstream.
// If possible the Decoder should be RetireDecoder'd when it is no longer
// needed, this will avoid heap allocations.
func (pr *PkgDecoder) TempDecoder(k RelocKind, idx Index, marker SyncMarker) Decoder {
r := pr.TempDecoderRaw(k, idx)
r.Sync(marker)
return r
}
func (pr *PkgDecoder) RetireDecoder(d *Decoder) {
pr.scratchRelocEnt = d.Relocs
d.Relocs = nil
}
// NewDecoderRaw returns a Decoder for the given (section, index) pair.
//
// Most callers should use NewDecoder instead.
@ -188,6 +205,30 @@ func (pr *PkgDecoder) NewDecoderRaw(k RelocKind, idx Index) Decoder {
return r
}
func (pr *PkgDecoder) TempDecoderRaw(k RelocKind, idx Index) Decoder {
r := Decoder{
common: pr,
k: k,
Idx: idx,
}
r.Data.Reset(pr.DataIdx(k, idx))
r.Sync(SyncRelocs)
l := r.Len()
if cap(pr.scratchRelocEnt) >= l {
r.Relocs = pr.scratchRelocEnt[:l]
pr.scratchRelocEnt = nil
} else {
r.Relocs = make([]RelocEnt, l)
}
for i := range r.Relocs {
r.Sync(SyncReloc)
r.Relocs[i] = RelocEnt{RelocKind(r.Len()), Index(r.Len())}
}
return r
}
// A Decoder provides methods for decoding an individual element's
// bitstream data.
type Decoder struct {
@ -410,8 +451,12 @@ func (r *Decoder) bigFloat() *big.Float {
// PeekPkgPath returns the package path for the specified package
// index.
func (pr *PkgDecoder) PeekPkgPath(idx Index) string {
r := pr.NewDecoder(RelocPkg, idx, SyncPkgDef)
path := r.String()
var path string
{
r := pr.TempDecoder(RelocPkg, idx, SyncPkgDef)
path = r.String()
pr.RetireDecoder(&r)
}
if path == "" {
path = pr.pkgPath
}
@ -421,14 +466,23 @@ func (pr *PkgDecoder) PeekPkgPath(idx Index) string {
// PeekObj returns the package path, object name, and CodeObj for the
// specified object index.
func (pr *PkgDecoder) PeekObj(idx Index) (string, string, CodeObj) {
r := pr.NewDecoder(RelocName, idx, SyncObject1)
r.Sync(SyncSym)
r.Sync(SyncPkg)
path := pr.PeekPkgPath(r.Reloc(RelocPkg))
name := r.String()
var ridx Index
var name string
var rcode int
{
r := pr.TempDecoder(RelocName, idx, SyncObject1)
r.Sync(SyncSym)
r.Sync(SyncPkg)
ridx = r.Reloc(RelocPkg)
name = r.String()
rcode = r.Code(SyncCodeObj)
pr.RetireDecoder(&r)
}
path := pr.PeekPkgPath(ridx)
assert(name != "")
tag := CodeObj(r.Code(SyncCodeObj))
tag := CodeObj(rcode)
return path, name, tag
}