diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:16:40 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:16:40 +0000 |
commit | 47ab3d4a42e9ab51c465c4322d2ec233f6324e6b (patch) | |
tree | a61a0ffd83f4a3def4b36e5c8e99630c559aa723 /src/encoding/gob/debug.go | |
parent | Initial commit. (diff) | |
download | golang-1.18-upstream.tar.xz golang-1.18-upstream.zip |
Adding upstream version 1.18.10.upstream/1.18.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/encoding/gob/debug.go')
-rw-r--r-- | src/encoding/gob/debug.go | 705 |
1 files changed, 705 insertions, 0 deletions
diff --git a/src/encoding/gob/debug.go b/src/encoding/gob/debug.go new file mode 100644 index 0000000..b6d5a3e --- /dev/null +++ b/src/encoding/gob/debug.go @@ -0,0 +1,705 @@ +// Copyright 2009 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. + +// Delete the next line to include in the gob package. +//go:build ignore + +package gob + +// This file is not normally included in the gob package. Used only for debugging the package itself. +// Except for reading uints, it is an implementation of a reader that is independent of +// the one implemented by Decoder. +// To enable the Debug function, delete the +build ignore line above and do +// go install + +import ( + "bytes" + "fmt" + "io" + "os" + "strings" + "sync" +) + +var dumpBytes = false // If true, print the remaining bytes in the input buffer at each item. + +// Init installs the debugging facility. If this file is not compiled in the +// package, the tests in codec_test.go are no-ops. +func init() { + debugFunc = Debug +} + +var ( + blanks = bytes.Repeat([]byte{' '}, 3*10) + empty = []byte(": <empty>\n") + tabs = strings.Repeat("\t", 100) +) + +// tab indents itself when printed. +type tab int + +func (t tab) String() string { + n := int(t) + if n > len(tabs) { + n = len(tabs) + } + return tabs[0:n] +} + +func (t tab) print() { + fmt.Fprint(os.Stderr, t) +} + +// A peekReader wraps an io.Reader, allowing one to peek ahead to see +// what's coming without stealing the data from the client of the Reader. +type peekReader struct { + r io.Reader + data []byte // read-ahead data +} + +// newPeekReader returns a peekReader that wraps r. +func newPeekReader(r io.Reader) *peekReader { + return &peekReader{r: r} +} + +// Read is the usual method. It will first take data that has been read ahead. +func (p *peekReader) Read(b []byte) (n int, err error) { + if len(p.data) == 0 { + return p.r.Read(b) + } + // Satisfy what's possible from the read-ahead data. + n = copy(b, p.data) + // Move data down to beginning of slice, to avoid endless growth + copy(p.data, p.data[n:]) + p.data = p.data[:len(p.data)-n] + return +} + +// peek returns as many bytes as possible from the unread +// portion of the stream, up to the length of b. +func (p *peekReader) peek(b []byte) (n int, err error) { + if len(p.data) > 0 { + n = copy(b, p.data) + if n == len(b) { + return + } + b = b[n:] + } + if len(b) == 0 { + return + } + m, e := io.ReadFull(p.r, b) + if m > 0 { + p.data = append(p.data, b[:m]...) + } + n += m + if e == io.ErrUnexpectedEOF { + // That means m > 0 but we reached EOF. If we got data + // we won't complain about not being able to peek enough. + if n > 0 { + e = nil + } else { + e = io.EOF + } + } + return n, e +} + +type debugger struct { + mutex sync.Mutex + remain int // the number of bytes known to remain in the input + remainingKnown bool // the value of 'remain' is valid + r *peekReader + wireType map[typeId]*wireType + tmp []byte // scratch space for decoding uints. +} + +// dump prints the next nBytes of the input. +// It arranges to print the output aligned from call to +// call, to make it easy to see what has been consumed. +func (deb *debugger) dump(format string, args ...any) { + if !dumpBytes { + return + } + fmt.Fprintf(os.Stderr, format+" ", args...) + if !deb.remainingKnown { + return + } + if deb.remain < 0 { + fmt.Fprintf(os.Stderr, "remaining byte count is negative! %d\n", deb.remain) + return + } + data := make([]byte, deb.remain) + n, _ := deb.r.peek(data) + if n == 0 { + os.Stderr.Write(empty) + return + } + b := new(bytes.Buffer) + fmt.Fprintf(b, "[%d]{\n", deb.remain) + // Blanks until first byte + lineLength := 0 + if n := len(data); n%10 != 0 { + lineLength = 10 - n%10 + fmt.Fprintf(b, "\t%s", blanks[:lineLength*3]) + } + // 10 bytes per line + for len(data) > 0 { + if lineLength == 0 { + fmt.Fprint(b, "\t") + } + m := 10 - lineLength + lineLength = 0 + if m > len(data) { + m = len(data) + } + fmt.Fprintf(b, "% x\n", data[:m]) + data = data[m:] + } + fmt.Fprint(b, "}\n") + os.Stderr.Write(b.Bytes()) +} + +// Debug prints a human-readable representation of the gob data read from r. +// It is a no-op unless debugging was enabled when the package was built. +func Debug(r io.Reader) { + err := debug(r) + if err != nil { + fmt.Fprintf(os.Stderr, "gob debug: %s\n", err) + } +} + +// debug implements Debug, but catches panics and returns +// them as errors to be printed by Debug. +func debug(r io.Reader) (err error) { + defer catchError(&err) + fmt.Fprintln(os.Stderr, "Start of debugging") + deb := &debugger{ + r: newPeekReader(r), + wireType: make(map[typeId]*wireType), + tmp: make([]byte, 16), + } + if b, ok := r.(*bytes.Buffer); ok { + deb.remain = b.Len() + deb.remainingKnown = true + } + deb.gobStream() + return +} + +// note that we've consumed some bytes +func (deb *debugger) consumed(n int) { + if deb.remainingKnown { + deb.remain -= n + } +} + +// int64 decodes and returns the next integer, which must be present. +// Don't call this if you could be at EOF. +func (deb *debugger) int64() int64 { + return toInt(deb.uint64()) +} + +// uint64 returns and decodes the next unsigned integer, which must be present. +// Don't call this if you could be at EOF. +// TODO: handle errors better. +func (deb *debugger) uint64() uint64 { + n, w, err := decodeUintReader(deb.r, deb.tmp) + if err != nil { + errorf("debug: read error: %s", err) + } + deb.consumed(w) + return n +} + +// GobStream: +// DelimitedMessage* (until EOF) +func (deb *debugger) gobStream() { + // Make sure we're single-threaded through here. + deb.mutex.Lock() + defer deb.mutex.Unlock() + + for deb.delimitedMessage(0) { + } +} + +// DelimitedMessage: +// uint(lengthOfMessage) Message +func (deb *debugger) delimitedMessage(indent tab) bool { + for { + n := deb.loadBlock(true) + if n < 0 { + return false + } + deb.dump("Delimited message of length %d", n) + deb.message(indent) + } + return true +} + +// loadBlock preps us to read a message +// of the length specified next in the input. It returns +// the length of the block. The argument tells whether +// an EOF is acceptable now. If it is and one is found, +// the return value is negative. +func (deb *debugger) loadBlock(eofOK bool) int { + n64, w, err := decodeUintReader(deb.r, deb.tmp) // deb.uint64 will error at EOF + if err != nil { + if eofOK && err == io.EOF { + return -1 + } + errorf("debug: unexpected error: %s", err) + } + deb.consumed(w) + n := int(n64) + if n < 0 { + errorf("huge value for message length: %d", n64) + } + return int(n) +} + +// Message: +// TypeSequence TypedValue +// TypeSequence +// (TypeDefinition DelimitedTypeDefinition*)? +// DelimitedTypeDefinition: +// uint(lengthOfTypeDefinition) TypeDefinition +// TypedValue: +// int(typeId) Value +func (deb *debugger) message(indent tab) bool { + for { + // Convert the uint64 to a signed integer typeId + uid := deb.int64() + id := typeId(uid) + deb.dump("type id=%d", id) + if id < 0 { + deb.typeDefinition(indent, -id) + n := deb.loadBlock(false) + deb.dump("Message of length %d", n) + continue + } else { + deb.value(indent, id) + break + } + } + return true +} + +// Helper methods to make it easy to scan a type descriptor. + +// common returns the CommonType at the input point. +func (deb *debugger) common() CommonType { + fieldNum := -1 + name := "" + id := typeId(0) + for { + delta := deb.delta(-1) + if delta == 0 { + break + } + fieldNum += delta + switch fieldNum { + case 0: + name = deb.string() + case 1: + // Id typeId + id = deb.typeId() + default: + errorf("corrupted CommonType, delta is %d fieldNum is %d", delta, fieldNum) + } + } + return CommonType{name, id} +} + +// uint returns the unsigned int at the input point, as a uint (not uint64). +func (deb *debugger) uint() uint { + return uint(deb.uint64()) +} + +// int returns the signed int at the input point, as an int (not int64). +func (deb *debugger) int() int { + return int(deb.int64()) +} + +// typeId returns the type id at the input point. +func (deb *debugger) typeId() typeId { + return typeId(deb.int64()) +} + +// string returns the string at the input point. +func (deb *debugger) string() string { + x := int(deb.uint64()) + b := make([]byte, x) + nb, _ := deb.r.Read(b) + if nb != x { + errorf("corrupted type") + } + deb.consumed(nb) + return string(b) +} + +// delta returns the field delta at the input point. The expect argument, +// if non-negative, identifies what the value should be. +func (deb *debugger) delta(expect int) int { + delta := int(deb.uint64()) + if delta < 0 || (expect >= 0 && delta != expect) { + errorf("decode: corrupted type: delta %d expected %d", delta, expect) + } + return delta +} + +// TypeDefinition: +// [int(-typeId) (already read)] encodingOfWireType +func (deb *debugger) typeDefinition(indent tab, id typeId) { + deb.dump("type definition for id %d", id) + // Encoding is of a wireType. Decode the structure as usual + fieldNum := -1 + wire := new(wireType) + // A wireType defines a single field. + delta := deb.delta(-1) + fieldNum += delta + switch fieldNum { + case 0: // array type, one field of {{Common}, elem, length} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + // Field number 1 is type Id of elem + deb.delta(1) + id := deb.typeId() + // Field number 3 is length + deb.delta(1) + length := deb.int() + wire.ArrayT = &arrayType{com, id, length} + + case 1: // slice type, one field of {{Common}, elem} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + // Field number 1 is type Id of elem + deb.delta(1) + id := deb.typeId() + wire.SliceT = &sliceType{com, id} + + case 2: // struct type, one field of {{Common}, []fieldType} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + // Field number 1 is slice of FieldType + deb.delta(1) + numField := int(deb.uint()) + field := make([]*fieldType, numField) + for i := 0; i < numField; i++ { + field[i] = new(fieldType) + deb.delta(1) // field 0 of fieldType: name + field[i].Name = deb.string() + deb.delta(1) // field 1 of fieldType: id + field[i].Id = deb.typeId() + deb.delta(0) // end of fieldType + } + wire.StructT = &structType{com, field} + + case 3: // map type, one field of {{Common}, key, elem} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + // Field number 1 is type Id of key + deb.delta(1) + keyId := deb.typeId() + // Field number 2 is type Id of elem + deb.delta(1) + elemId := deb.typeId() + wire.MapT = &mapType{com, keyId, elemId} + case 4: // GobEncoder type, one field of {{Common}} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + wire.GobEncoderT = &gobEncoderType{com} + case 5: // BinaryMarshaler type, one field of {{Common}} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + wire.BinaryMarshalerT = &gobEncoderType{com} + case 6: // TextMarshaler type, one field of {{Common}} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + wire.TextMarshalerT = &gobEncoderType{com} + default: + errorf("bad field in type %d", fieldNum) + } + deb.printWireType(indent, wire) + deb.delta(0) // end inner type (arrayType, etc.) + deb.delta(0) // end wireType + // Remember we've seen this type. + deb.wireType[id] = wire +} + +// Value: +// SingletonValue | StructValue +func (deb *debugger) value(indent tab, id typeId) { + wire, ok := deb.wireType[id] + if ok && wire.StructT != nil { + deb.structValue(indent, id) + } else { + deb.singletonValue(indent, id) + } +} + +// SingletonValue: +// uint(0) FieldValue +func (deb *debugger) singletonValue(indent tab, id typeId) { + deb.dump("Singleton value") + // is it a builtin type? + wire := deb.wireType[id] + _, ok := builtinIdToType[id] + if !ok && wire == nil { + errorf("type id %d not defined", id) + } + m := deb.uint64() + if m != 0 { + errorf("expected zero; got %d", m) + } + deb.fieldValue(indent, id) +} + +// InterfaceValue: +// NilInterfaceValue | NonNilInterfaceValue +func (deb *debugger) interfaceValue(indent tab) { + deb.dump("Start of interface value") + if nameLen := deb.uint64(); nameLen == 0 { + deb.nilInterfaceValue(indent) + } else { + deb.nonNilInterfaceValue(indent, int(nameLen)) + } +} + +// NilInterfaceValue: +// uint(0) [already read] +func (deb *debugger) nilInterfaceValue(indent tab) int { + fmt.Fprintf(os.Stderr, "%snil interface\n", indent) + return 0 +} + +// NonNilInterfaceValue: +// ConcreteTypeName TypeSequence InterfaceContents +// ConcreteTypeName: +// uint(lengthOfName) [already read=n] name +// InterfaceContents: +// int(concreteTypeId) DelimitedValue +// DelimitedValue: +// uint(length) Value +func (deb *debugger) nonNilInterfaceValue(indent tab, nameLen int) { + // ConcreteTypeName + b := make([]byte, nameLen) + deb.r.Read(b) // TODO: CHECK THESE READS!! + deb.consumed(nameLen) + name := string(b) + + for { + id := deb.typeId() + if id < 0 { + deb.typeDefinition(indent, -id) + n := deb.loadBlock(false) + deb.dump("Nested message of length %d", n) + } else { + // DelimitedValue + x := deb.uint64() // in case we want to ignore the value; we don't. + fmt.Fprintf(os.Stderr, "%sinterface value, type %q id=%d; valueLength %d\n", indent, name, id, x) + deb.value(indent, id) + break + } + } +} + +// printCommonType prints a common type; used by printWireType. +func (deb *debugger) printCommonType(indent tab, kind string, common *CommonType) { + indent.print() + fmt.Fprintf(os.Stderr, "%s %q id=%d\n", kind, common.Name, common.Id) +} + +// printWireType prints the contents of a wireType. +func (deb *debugger) printWireType(indent tab, wire *wireType) { + fmt.Fprintf(os.Stderr, "%stype definition {\n", indent) + indent++ + switch { + case wire.ArrayT != nil: + deb.printCommonType(indent, "array", &wire.ArrayT.CommonType) + fmt.Fprintf(os.Stderr, "%slen %d\n", indent+1, wire.ArrayT.Len) + fmt.Fprintf(os.Stderr, "%selemid %d\n", indent+1, wire.ArrayT.Elem) + case wire.MapT != nil: + deb.printCommonType(indent, "map", &wire.MapT.CommonType) + fmt.Fprintf(os.Stderr, "%skey id=%d\n", indent+1, wire.MapT.Key) + fmt.Fprintf(os.Stderr, "%selem id=%d\n", indent+1, wire.MapT.Elem) + case wire.SliceT != nil: + deb.printCommonType(indent, "slice", &wire.SliceT.CommonType) + fmt.Fprintf(os.Stderr, "%selem id=%d\n", indent+1, wire.SliceT.Elem) + case wire.StructT != nil: + deb.printCommonType(indent, "struct", &wire.StructT.CommonType) + for i, field := range wire.StructT.Field { + fmt.Fprintf(os.Stderr, "%sfield %d:\t%s\tid=%d\n", indent+1, i, field.Name, field.Id) + } + case wire.GobEncoderT != nil: + deb.printCommonType(indent, "GobEncoder", &wire.GobEncoderT.CommonType) + } + indent-- + fmt.Fprintf(os.Stderr, "%s}\n", indent) +} + +// fieldValue prints a value of any type, such as a struct field. +// FieldValue: +// builtinValue | ArrayValue | MapValue | SliceValue | StructValue | InterfaceValue +func (deb *debugger) fieldValue(indent tab, id typeId) { + _, ok := builtinIdToType[id] + if ok { + if id == tInterface { + deb.interfaceValue(indent) + } else { + deb.printBuiltin(indent, id) + } + return + } + wire, ok := deb.wireType[id] + if !ok { + errorf("type id %d not defined", id) + } + switch { + case wire.ArrayT != nil: + deb.arrayValue(indent, wire) + case wire.MapT != nil: + deb.mapValue(indent, wire) + case wire.SliceT != nil: + deb.sliceValue(indent, wire) + case wire.StructT != nil: + deb.structValue(indent, id) + case wire.GobEncoderT != nil: + deb.gobEncoderValue(indent, id) + default: + panic("bad wire type for field") + } +} + +// printBuiltin prints a value not of a fundamental type, that is, +// one whose type is known to gobs at bootstrap time. +func (deb *debugger) printBuiltin(indent tab, id typeId) { + switch id { + case tBool: + x := deb.int64() + if x == 0 { + fmt.Fprintf(os.Stderr, "%sfalse\n", indent) + } else { + fmt.Fprintf(os.Stderr, "%strue\n", indent) + } + case tInt: + x := deb.int64() + fmt.Fprintf(os.Stderr, "%s%d\n", indent, x) + case tUint: + x := deb.uint64() + fmt.Fprintf(os.Stderr, "%s%d\n", indent, x) + case tFloat: + x := deb.uint64() + fmt.Fprintf(os.Stderr, "%s%g\n", indent, float64FromBits(x)) + case tComplex: + r := deb.uint64() + i := deb.uint64() + fmt.Fprintf(os.Stderr, "%s%g+%gi\n", indent, float64FromBits(r), float64FromBits(i)) + case tBytes: + x := int(deb.uint64()) + b := make([]byte, x) + deb.r.Read(b) + deb.consumed(x) + fmt.Fprintf(os.Stderr, "%s{% x}=%q\n", indent, b, b) + case tString: + x := int(deb.uint64()) + b := make([]byte, x) + deb.r.Read(b) + deb.consumed(x) + fmt.Fprintf(os.Stderr, "%s%q\n", indent, b) + default: + panic("unknown builtin") + } +} + +// ArrayValue: +// uint(n) FieldValue*n +func (deb *debugger) arrayValue(indent tab, wire *wireType) { + elemId := wire.ArrayT.Elem + u := deb.uint64() + length := int(u) + for i := 0; i < length; i++ { + deb.fieldValue(indent, elemId) + } + if length != wire.ArrayT.Len { + fmt.Fprintf(os.Stderr, "%s(wrong length for array: %d should be %d)\n", indent, length, wire.ArrayT.Len) + } +} + +// MapValue: +// uint(n) (FieldValue FieldValue)*n [n (key, value) pairs] +func (deb *debugger) mapValue(indent tab, wire *wireType) { + keyId := wire.MapT.Key + elemId := wire.MapT.Elem + u := deb.uint64() + length := int(u) + for i := 0; i < length; i++ { + deb.fieldValue(indent+1, keyId) + deb.fieldValue(indent+1, elemId) + } +} + +// SliceValue: +// uint(n) (n FieldValue) +func (deb *debugger) sliceValue(indent tab, wire *wireType) { + elemId := wire.SliceT.Elem + u := deb.uint64() + length := int(u) + deb.dump("Start of slice of length %d", length) + + for i := 0; i < length; i++ { + deb.fieldValue(indent, elemId) + } +} + +// StructValue: +// (uint(fieldDelta) FieldValue)* +func (deb *debugger) structValue(indent tab, id typeId) { + deb.dump("Start of struct value of %q id=%d\n<<\n", id.name(), id) + fmt.Fprintf(os.Stderr, "%s%s struct {\n", indent, id.name()) + wire, ok := deb.wireType[id] + if !ok { + errorf("type id %d not defined", id) + } + strct := wire.StructT + fieldNum := -1 + indent++ + for { + delta := deb.uint64() + if delta == 0 { // struct terminator is zero delta fieldnum + break + } + fieldNum += int(delta) + if fieldNum < 0 || fieldNum >= len(strct.Field) { + deb.dump("field number out of range: prevField=%d delta=%d", fieldNum-int(delta), delta) + break + } + fmt.Fprintf(os.Stderr, "%sfield %d:\t%s\n", indent, fieldNum, wire.StructT.Field[fieldNum].Name) + deb.fieldValue(indent+1, strct.Field[fieldNum].Id) + } + indent-- + fmt.Fprintf(os.Stderr, "%s} // end %s struct\n", indent, id.name()) + deb.dump(">> End of struct value of type %d %q", id, id.name()) +} + +// GobEncoderValue: +// uint(n) byte*n +func (deb *debugger) gobEncoderValue(indent tab, id typeId) { + len := deb.uint64() + deb.dump("GobEncoder value of %q id=%d, length %d\n", id.name(), id, len) + fmt.Fprintf(os.Stderr, "%s%s (implements GobEncoder)\n", indent, id.name()) + data := make([]byte, len) + _, err := deb.r.Read(data) + if err != nil { + errorf("gobEncoder data read: %s", err) + } + fmt.Fprintf(os.Stderr, "%s[% .2x]\n", indent+1, data) +} |