From 351c15d28e0444fd8a78c510a0c4d62ed433c758 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 7 Aug 2024 00:21:12 +0200 Subject: Genesis commit --- vendor/golang.org/x/text/internal/catmsg/catmsg.go | 417 +++++++++++++++++++++ vendor/golang.org/x/text/internal/catmsg/codec.go | 407 ++++++++++++++++++++ vendor/golang.org/x/text/internal/catmsg/varint.go | 62 +++ 3 files changed, 886 insertions(+) create mode 100644 vendor/golang.org/x/text/internal/catmsg/catmsg.go create mode 100644 vendor/golang.org/x/text/internal/catmsg/codec.go create mode 100644 vendor/golang.org/x/text/internal/catmsg/varint.go (limited to 'vendor/golang.org/x/text/internal/catmsg') diff --git a/vendor/golang.org/x/text/internal/catmsg/catmsg.go b/vendor/golang.org/x/text/internal/catmsg/catmsg.go new file mode 100644 index 0000000..1b257a7 --- /dev/null +++ b/vendor/golang.org/x/text/internal/catmsg/catmsg.go @@ -0,0 +1,417 @@ +// Copyright 2017 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 catmsg contains support types for package x/text/message/catalog. +// +// This package contains the low-level implementations of Message used by the +// catalog package and provides primitives for other packages to implement their +// own. For instance, the plural package provides functionality for selecting +// translation strings based on the plural category of substitution arguments. +// +// # Encoding and Decoding +// +// Catalogs store Messages encoded as a single string. Compiling a message into +// a string both results in compacter representation and speeds up evaluation. +// +// A Message must implement a Compile method to convert its arbitrary +// representation to a string. The Compile method takes an Encoder which +// facilitates serializing the message. Encoders also provide more context of +// the messages's creation (such as for which language the message is intended), +// which may not be known at the time of the creation of the message. +// +// Each message type must also have an accompanying decoder registered to decode +// the message. This decoder takes a Decoder argument which provides the +// counterparts for the decoding. +// +// # Renderers +// +// A Decoder must be initialized with a Renderer implementation. These +// implementations must be provided by packages that use Catalogs, typically +// formatting packages such as x/text/message. A typical user will not need to +// worry about this type; it is only relevant to packages that do string +// formatting and want to use the catalog package to handle localized strings. +// +// A package that uses catalogs for selecting strings receives selection results +// as sequence of substrings passed to the Renderer. The following snippet shows +// how to express the above example using the message package. +// +// message.Set(language.English, "You are %d minute(s) late.", +// catalog.Var("minutes", plural.Select(1, "one", "minute")), +// catalog.String("You are %[1]d ${minutes} late.")) +// +// p := message.NewPrinter(language.English) +// p.Printf("You are %d minute(s) late.", 5) // always 5 minutes late. +// +// To evaluate the Printf, package message wraps the arguments in a Renderer +// that is passed to the catalog for message decoding. The call sequence that +// results from evaluating the above message, assuming the person is rather +// tardy, is: +// +// Render("You are %[1]d ") +// Arg(1) +// Render("minutes") +// Render(" late.") +// +// The calls to Arg is caused by the plural.Select execution, which evaluates +// the argument to determine whether the singular or plural message form should +// be selected. The calls to Render reports the partial results to the message +// package for further evaluation. +package catmsg + +import ( + "errors" + "fmt" + "strconv" + "strings" + "sync" + + "golang.org/x/text/language" +) + +// A Handle refers to a registered message type. +type Handle int + +// A Handler decodes and evaluates data compiled by a Message and sends the +// result to the Decoder. The output may depend on the value of the substitution +// arguments, accessible by the Decoder's Arg method. The Handler returns false +// if there is no translation for the given substitution arguments. +type Handler func(d *Decoder) bool + +// Register records the existence of a message type and returns a Handle that +// can be used in the Encoder's EncodeMessageType method to create such +// messages. The prefix of the name should be the package path followed by +// an optional disambiguating string. +// Register will panic if a handle for the same name was already registered. +func Register(name string, handler Handler) Handle { + mutex.Lock() + defer mutex.Unlock() + + if _, ok := names[name]; ok { + panic(fmt.Errorf("catmsg: handler for %q already exists", name)) + } + h := Handle(len(handlers)) + names[name] = h + handlers = append(handlers, handler) + return h +} + +// These handlers require fixed positions in the handlers slice. +const ( + msgVars Handle = iota + msgFirst + msgRaw + msgString + msgAffix + // Leave some arbitrary room for future expansion: 20 should suffice. + numInternal = 20 +) + +const prefix = "golang.org/x/text/internal/catmsg." + +var ( + // TODO: find a more stable way to link handles to message types. + mutex sync.Mutex + names = map[string]Handle{ + prefix + "Vars": msgVars, + prefix + "First": msgFirst, + prefix + "Raw": msgRaw, + prefix + "String": msgString, + prefix + "Affix": msgAffix, + } + handlers = make([]Handler, numInternal) +) + +func init() { + // This handler is a message type wrapper that initializes a decoder + // with a variable block. This message type, if present, is always at the + // start of an encoded message. + handlers[msgVars] = func(d *Decoder) bool { + blockSize := int(d.DecodeUint()) + d.vars = d.data[:blockSize] + d.data = d.data[blockSize:] + return d.executeMessage() + } + + // First takes the first message in a sequence that results in a match for + // the given substitution arguments. + handlers[msgFirst] = func(d *Decoder) bool { + for !d.Done() { + if d.ExecuteMessage() { + return true + } + } + return false + } + + handlers[msgRaw] = func(d *Decoder) bool { + d.Render(d.data) + return true + } + + // A String message alternates between a string constant and a variable + // substitution. + handlers[msgString] = func(d *Decoder) bool { + for !d.Done() { + if str := d.DecodeString(); str != "" { + d.Render(str) + } + if d.Done() { + break + } + d.ExecuteSubstitution() + } + return true + } + + handlers[msgAffix] = func(d *Decoder) bool { + // TODO: use an alternative method for common cases. + prefix := d.DecodeString() + suffix := d.DecodeString() + if prefix != "" { + d.Render(prefix) + } + ret := d.ExecuteMessage() + if suffix != "" { + d.Render(suffix) + } + return ret + } +} + +var ( + // ErrIncomplete indicates a compiled message does not define translations + // for all possible argument values. If this message is returned, evaluating + // a message may result in the ErrNoMatch error. + ErrIncomplete = errors.New("catmsg: incomplete message; may not give result for all inputs") + + // ErrNoMatch indicates no translation message matched the given input + // parameters when evaluating a message. + ErrNoMatch = errors.New("catmsg: no translation for inputs") +) + +// A Message holds a collection of translations for the same phrase that may +// vary based on the values of substitution arguments. +type Message interface { + // Compile encodes the format string(s) of the message as a string for later + // evaluation. + // + // The first call Compile makes on the encoder must be EncodeMessageType. + // The handle passed to this call may either be a handle returned by + // Register to encode a single custom message, or HandleFirst followed by + // a sequence of calls to EncodeMessage. + // + // Compile must return ErrIncomplete if it is possible for evaluation to + // not match any translation for a given set of formatting parameters. + // For example, selecting a translation based on plural form may not yield + // a match if the form "Other" is not one of the selectors. + // + // Compile may return any other application-specific error. For backwards + // compatibility with package like fmt, which often do not do sanity + // checking of format strings ahead of time, Compile should still make an + // effort to have some sensible fallback in case of an error. + Compile(e *Encoder) error +} + +// Compile converts a Message to a data string that can be stored in a Catalog. +// The resulting string can subsequently be decoded by passing to the Execute +// method of a Decoder. +func Compile(tag language.Tag, macros Dictionary, m Message) (data string, err error) { + // TODO: pass macros so they can be used for validation. + v := &Encoder{inBody: true} // encoder for variables + v.root = v + e := &Encoder{root: v, parent: v, tag: tag} // encoder for messages + err = m.Compile(e) + // This package serves te message package, which in turn is meant to be a + // drop-in replacement for fmt. With the fmt package, format strings are + // evaluated lazily and errors are handled by substituting strings in the + // result, rather then returning an error. Dealing with multiple languages + // makes it more important to check errors ahead of time. We chose to be + // consistent and compatible and allow graceful degradation in case of + // errors. + buf := e.buf[stripPrefix(e.buf):] + if len(v.buf) > 0 { + // Prepend variable block. + b := make([]byte, 1+maxVarintBytes+len(v.buf)+len(buf)) + b[0] = byte(msgVars) + b = b[:1+encodeUint(b[1:], uint64(len(v.buf)))] + b = append(b, v.buf...) + b = append(b, buf...) + buf = b + } + if err == nil { + err = v.err + } + return string(buf), err +} + +// FirstOf is a message type that prints the first message in the sequence that +// resolves to a match for the given substitution arguments. +type FirstOf []Message + +// Compile implements Message. +func (s FirstOf) Compile(e *Encoder) error { + e.EncodeMessageType(msgFirst) + err := ErrIncomplete + for i, m := range s { + if err == nil { + return fmt.Errorf("catalog: message argument %d is complete and blocks subsequent messages", i-1) + } + err = e.EncodeMessage(m) + } + return err +} + +// Var defines a message that can be substituted for a placeholder of the same +// name. If an expression does not result in a string after evaluation, Name is +// used as the substitution. For example: +// +// Var{ +// Name: "minutes", +// Message: plural.Select(1, "one", "minute"), +// } +// +// will resolve to minute for singular and minutes for plural forms. +type Var struct { + Name string + Message Message +} + +var errIsVar = errors.New("catmsg: variable used as message") + +// Compile implements Message. +// +// Note that this method merely registers a variable; it does not create an +// encoded message. +func (v *Var) Compile(e *Encoder) error { + if err := e.addVar(v.Name, v.Message); err != nil { + return err + } + // Using a Var by itself is an error. If it is in a sequence followed by + // other messages referring to it, this error will be ignored. + return errIsVar +} + +// Raw is a message consisting of a single format string that is passed as is +// to the Renderer. +// +// Note that a Renderer may still do its own variable substitution. +type Raw string + +// Compile implements Message. +func (r Raw) Compile(e *Encoder) (err error) { + e.EncodeMessageType(msgRaw) + // Special case: raw strings don't have a size encoding and so don't use + // EncodeString. + e.buf = append(e.buf, r...) + return nil +} + +// String is a message consisting of a single format string which contains +// placeholders that may be substituted with variables. +// +// Variable substitutions are marked with placeholders and a variable name of +// the form ${name}. Any other substitutions such as Go templates or +// printf-style substitutions are left to be done by the Renderer. +// +// When evaluation a string interpolation, a Renderer will receive separate +// calls for each placeholder and interstitial string. For example, for the +// message: "%[1]v ${invites} %[2]v to ${their} party." The sequence of calls +// is: +// +// d.Render("%[1]v ") +// d.Arg(1) +// d.Render(resultOfInvites) +// d.Render(" %[2]v to ") +// d.Arg(2) +// d.Render(resultOfTheir) +// d.Render(" party.") +// +// where the messages for "invites" and "their" both use a plural.Select +// referring to the first argument. +// +// Strings may also invoke macros. Macros are essentially variables that can be +// reused. Macros may, for instance, be used to make selections between +// different conjugations of a verb. See the catalog package description for an +// overview of macros. +type String string + +// Compile implements Message. It parses the placeholder formats and returns +// any error. +func (s String) Compile(e *Encoder) (err error) { + msg := string(s) + const subStart = "${" + hasHeader := false + p := 0 + b := []byte{} + for { + i := strings.Index(msg[p:], subStart) + if i == -1 { + break + } + b = append(b, msg[p:p+i]...) + p += i + len(subStart) + if i = strings.IndexByte(msg[p:], '}'); i == -1 { + b = append(b, "$!(MISSINGBRACE)"...) + err = fmt.Errorf("catmsg: missing '}'") + p = len(msg) + break + } + name := strings.TrimSpace(msg[p : p+i]) + if q := strings.IndexByte(name, '('); q == -1 { + if !hasHeader { + hasHeader = true + e.EncodeMessageType(msgString) + } + e.EncodeString(string(b)) + e.EncodeSubstitution(name) + b = b[:0] + } else if j := strings.IndexByte(name[q:], ')'); j == -1 { + // TODO: what should the error be? + b = append(b, "$!(MISSINGPAREN)"...) + err = fmt.Errorf("catmsg: missing ')'") + } else if x, sErr := strconv.ParseUint(strings.TrimSpace(name[q+1:q+j]), 10, 32); sErr != nil { + // TODO: handle more than one argument + b = append(b, "$!(BADNUM)"...) + err = fmt.Errorf("catmsg: invalid number %q", strings.TrimSpace(name[q+1:q+j])) + } else { + if !hasHeader { + hasHeader = true + e.EncodeMessageType(msgString) + } + e.EncodeString(string(b)) + e.EncodeSubstitution(name[:q], int(x)) + b = b[:0] + } + p += i + 1 + } + b = append(b, msg[p:]...) + if !hasHeader { + // Simplify string to a raw string. + Raw(string(b)).Compile(e) + } else if len(b) > 0 { + e.EncodeString(string(b)) + } + return err +} + +// Affix is a message that adds a prefix and suffix to another message. +// This is mostly used add back whitespace to a translation that was stripped +// before sending it out. +type Affix struct { + Message Message + Prefix string + Suffix string +} + +// Compile implements Message. +func (a Affix) Compile(e *Encoder) (err error) { + // TODO: consider adding a special message type that just adds a single + // return. This is probably common enough to handle the majority of cases. + // Get some stats first, though. + e.EncodeMessageType(msgAffix) + e.EncodeString(a.Prefix) + e.EncodeString(a.Suffix) + e.EncodeMessage(a.Message) + return nil +} diff --git a/vendor/golang.org/x/text/internal/catmsg/codec.go b/vendor/golang.org/x/text/internal/catmsg/codec.go new file mode 100644 index 0000000..49c9fc9 --- /dev/null +++ b/vendor/golang.org/x/text/internal/catmsg/codec.go @@ -0,0 +1,407 @@ +// Copyright 2017 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 catmsg + +import ( + "errors" + "fmt" + + "golang.org/x/text/language" +) + +// A Renderer renders a Message. +type Renderer interface { + // Render renders the given string. The given string may be interpreted as a + // format string, such as the one used by the fmt package or a template. + Render(s string) + + // Arg returns the i-th argument passed to format a message. This method + // should return nil if there is no such argument. Messages need access to + // arguments to allow selecting a message based on linguistic features of + // those arguments. + Arg(i int) interface{} +} + +// A Dictionary specifies a source of messages, including variables or macros. +type Dictionary interface { + // Lookup returns the message for the given key. It returns false for ok if + // such a message could not be found. + Lookup(key string) (data string, ok bool) + + // TODO: consider returning an interface, instead of a string. This will + // allow implementations to do their own message type decoding. +} + +// An Encoder serializes a Message to a string. +type Encoder struct { + // The root encoder is used for storing encoded variables. + root *Encoder + // The parent encoder provides the surrounding scopes for resolving variable + // names. + parent *Encoder + + tag language.Tag + + // buf holds the encoded message so far. After a message completes encoding, + // the contents of buf, prefixed by the encoded length, are flushed to the + // parent buffer. + buf []byte + + // vars is the lookup table of variables in the current scope. + vars []keyVal + + err error + inBody bool // if false next call must be EncodeMessageType +} + +type keyVal struct { + key string + offset int +} + +// Language reports the language for which the encoded message will be stored +// in the Catalog. +func (e *Encoder) Language() language.Tag { return e.tag } + +func (e *Encoder) setError(err error) { + if e.root.err == nil { + e.root.err = err + } +} + +// EncodeUint encodes x. +func (e *Encoder) EncodeUint(x uint64) { + e.checkInBody() + var buf [maxVarintBytes]byte + n := encodeUint(buf[:], x) + e.buf = append(e.buf, buf[:n]...) +} + +// EncodeString encodes s. +func (e *Encoder) EncodeString(s string) { + e.checkInBody() + e.EncodeUint(uint64(len(s))) + e.buf = append(e.buf, s...) +} + +// EncodeMessageType marks the current message to be of type h. +// +// It must be the first call of a Message's Compile method. +func (e *Encoder) EncodeMessageType(h Handle) { + if e.inBody { + panic("catmsg: EncodeMessageType not the first method called") + } + e.inBody = true + e.EncodeUint(uint64(h)) +} + +// EncodeMessage serializes the given message inline at the current position. +func (e *Encoder) EncodeMessage(m Message) error { + e = &Encoder{root: e.root, parent: e, tag: e.tag} + err := m.Compile(e) + if _, ok := m.(*Var); !ok { + e.flushTo(e.parent) + } + return err +} + +func (e *Encoder) checkInBody() { + if !e.inBody { + panic("catmsg: expected prior call to EncodeMessageType") + } +} + +// stripPrefix indicates the number of prefix bytes that must be stripped to +// turn a single-element sequence into a message that is just this single member +// without its size prefix. If the message can be stripped, b[1:n] contains the +// size prefix. +func stripPrefix(b []byte) (n int) { + if len(b) > 0 && Handle(b[0]) == msgFirst { + x, n, _ := decodeUint(b[1:]) + if 1+n+int(x) == len(b) { + return 1 + n + } + } + return 0 +} + +func (e *Encoder) flushTo(dst *Encoder) { + data := e.buf + p := stripPrefix(data) + if p > 0 { + data = data[1:] + } else { + // Prefix the size. + dst.EncodeUint(uint64(len(data))) + } + dst.buf = append(dst.buf, data...) +} + +func (e *Encoder) addVar(key string, m Message) error { + for _, v := range e.parent.vars { + if v.key == key { + err := fmt.Errorf("catmsg: duplicate variable %q", key) + e.setError(err) + return err + } + } + scope := e.parent + // If a variable message is Incomplete, and does not evaluate to a message + // during execution, we fall back to the variable name. We encode this by + // appending the variable name if the message reports it's incomplete. + + err := m.Compile(e) + if err != ErrIncomplete { + e.setError(err) + } + switch { + case len(e.buf) == 1 && Handle(e.buf[0]) == msgFirst: // empty sequence + e.buf = e.buf[:0] + e.inBody = false + fallthrough + case len(e.buf) == 0: + // Empty message. + if err := String(key).Compile(e); err != nil { + e.setError(err) + } + case err == ErrIncomplete: + if Handle(e.buf[0]) != msgFirst { + seq := &Encoder{root: e.root, parent: e} + seq.EncodeMessageType(msgFirst) + e.flushTo(seq) + e = seq + } + // e contains a sequence; append the fallback string. + e.EncodeMessage(String(key)) + } + + // Flush result to variable heap. + offset := len(e.root.buf) + e.flushTo(e.root) + e.buf = e.buf[:0] + + // Record variable offset in current scope. + scope.vars = append(scope.vars, keyVal{key: key, offset: offset}) + return err +} + +const ( + substituteVar = iota + substituteMacro + substituteError +) + +// EncodeSubstitution inserts a resolved reference to a variable or macro. +// +// This call must be matched with a call to ExecuteSubstitution at decoding +// time. +func (e *Encoder) EncodeSubstitution(name string, arguments ...int) { + if arity := len(arguments); arity > 0 { + // TODO: also resolve macros. + e.EncodeUint(substituteMacro) + e.EncodeString(name) + for _, a := range arguments { + e.EncodeUint(uint64(a)) + } + return + } + for scope := e; scope != nil; scope = scope.parent { + for _, v := range scope.vars { + if v.key != name { + continue + } + e.EncodeUint(substituteVar) // TODO: support arity > 0 + e.EncodeUint(uint64(v.offset)) + return + } + } + // TODO: refer to dictionary-wide scoped variables. + e.EncodeUint(substituteError) + e.EncodeString(name) + e.setError(fmt.Errorf("catmsg: unknown var %q", name)) +} + +// A Decoder deserializes and evaluates messages that are encoded by an encoder. +type Decoder struct { + tag language.Tag + dst Renderer + macros Dictionary + + err error + vars string + data string + + macroArg int // TODO: allow more than one argument +} + +// NewDecoder returns a new Decoder. +// +// Decoders are designed to be reused for multiple invocations of Execute. +// Only one goroutine may call Execute concurrently. +func NewDecoder(tag language.Tag, r Renderer, macros Dictionary) *Decoder { + return &Decoder{ + tag: tag, + dst: r, + macros: macros, + } +} + +func (d *Decoder) setError(err error) { + if d.err == nil { + d.err = err + } +} + +// Language returns the language in which the message is being rendered. +// +// The destination language may be a child language of the language used for +// encoding. For instance, a decoding language of "pt-PT"" is consistent with an +// encoding language of "pt". +func (d *Decoder) Language() language.Tag { return d.tag } + +// Done reports whether there are more bytes to process in this message. +func (d *Decoder) Done() bool { return len(d.data) == 0 } + +// Render implements Renderer. +func (d *Decoder) Render(s string) { d.dst.Render(s) } + +// Arg implements Renderer. +// +// During evaluation of macros, the argument positions may be mapped to +// arguments that differ from the original call. +func (d *Decoder) Arg(i int) interface{} { + if d.macroArg != 0 { + if i != 1 { + panic("catmsg: only macros with single argument supported") + } + i = d.macroArg + } + return d.dst.Arg(i) +} + +// DecodeUint decodes a number that was encoded with EncodeUint and advances the +// position. +func (d *Decoder) DecodeUint() uint64 { + x, n, err := decodeUintString(d.data) + d.data = d.data[n:] + if err != nil { + d.setError(err) + } + return x +} + +// DecodeString decodes a string that was encoded with EncodeString and advances +// the position. +func (d *Decoder) DecodeString() string { + size := d.DecodeUint() + s := d.data[:size] + d.data = d.data[size:] + return s +} + +// SkipMessage skips the message at the current location and advances the +// position. +func (d *Decoder) SkipMessage() { + n := int(d.DecodeUint()) + d.data = d.data[n:] +} + +// Execute decodes and evaluates msg. +// +// Only one goroutine may call execute. +func (d *Decoder) Execute(msg string) error { + d.err = nil + if !d.execute(msg) { + return ErrNoMatch + } + return d.err +} + +func (d *Decoder) execute(msg string) bool { + saved := d.data + d.data = msg + ok := d.executeMessage() + d.data = saved + return ok +} + +// executeMessageFromData is like execute, but also decodes a leading message +// size and clips the given string accordingly. +// +// It reports the number of bytes consumed and whether a message was selected. +func (d *Decoder) executeMessageFromData(s string) (n int, ok bool) { + saved := d.data + d.data = s + size := int(d.DecodeUint()) + n = len(s) - len(d.data) + // Sanitize the setting. This allows skipping a size argument for + // RawString and method Done. + d.data = d.data[:size] + ok = d.executeMessage() + n += size - len(d.data) + d.data = saved + return n, ok +} + +var errUnknownHandler = errors.New("catmsg: string contains unsupported handler") + +// executeMessage reads the handle id, initializes the decoder and executes the +// message. It is assumed that all of d.data[d.p:] is the single message. +func (d *Decoder) executeMessage() bool { + if d.Done() { + // We interpret no data as a valid empty message. + return true + } + handle := d.DecodeUint() + + var fn Handler + mutex.Lock() + if int(handle) < len(handlers) { + fn = handlers[handle] + } + mutex.Unlock() + if fn == nil { + d.setError(errUnknownHandler) + d.execute(fmt.Sprintf("\x02$!(UNKNOWNMSGHANDLER=%#x)", handle)) + return true + } + return fn(d) +} + +// ExecuteMessage decodes and executes the message at the current position. +func (d *Decoder) ExecuteMessage() bool { + n, ok := d.executeMessageFromData(d.data) + d.data = d.data[n:] + return ok +} + +// ExecuteSubstitution executes the message corresponding to the substitution +// as encoded by EncodeSubstitution. +func (d *Decoder) ExecuteSubstitution() { + switch x := d.DecodeUint(); x { + case substituteVar: + offset := d.DecodeUint() + d.executeMessageFromData(d.vars[offset:]) + case substituteMacro: + name := d.DecodeString() + data, ok := d.macros.Lookup(name) + old := d.macroArg + // TODO: support macros of arity other than 1. + d.macroArg = int(d.DecodeUint()) + switch { + case !ok: + // TODO: detect this at creation time. + d.setError(fmt.Errorf("catmsg: undefined macro %q", name)) + fallthrough + case !d.execute(data): + d.dst.Render(name) // fall back to macro name. + } + d.macroArg = old + case substituteError: + d.dst.Render(d.DecodeString()) + default: + panic("catmsg: unreachable") + } +} diff --git a/vendor/golang.org/x/text/internal/catmsg/varint.go b/vendor/golang.org/x/text/internal/catmsg/varint.go new file mode 100644 index 0000000..a2cee2c --- /dev/null +++ b/vendor/golang.org/x/text/internal/catmsg/varint.go @@ -0,0 +1,62 @@ +// Copyright 2017 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 catmsg + +// This file implements varint encoding analogous to the one in encoding/binary. +// We need a string version of this function, so we add that here and then add +// the rest for consistency. + +import "errors" + +var ( + errIllegalVarint = errors.New("catmsg: illegal varint") + errVarintTooLarge = errors.New("catmsg: varint too large for uint64") +) + +const maxVarintBytes = 10 // maximum length of a varint + +// encodeUint encodes x as a variable-sized integer into buf and returns the +// number of bytes written. buf must be at least maxVarintBytes long +func encodeUint(buf []byte, x uint64) (n int) { + for ; x > 127; n++ { + buf[n] = 0x80 | uint8(x&0x7F) + x >>= 7 + } + buf[n] = uint8(x) + n++ + return n +} + +func decodeUintString(s string) (x uint64, size int, err error) { + i := 0 + for shift := uint(0); shift < 64; shift += 7 { + if i >= len(s) { + return 0, i, errIllegalVarint + } + b := uint64(s[i]) + i++ + x |= (b & 0x7F) << shift + if b&0x80 == 0 { + return x, i, nil + } + } + return 0, i, errVarintTooLarge +} + +func decodeUint(b []byte) (x uint64, size int, err error) { + i := 0 + for shift := uint(0); shift < 64; shift += 7 { + if i >= len(b) { + return 0, i, errIllegalVarint + } + c := uint64(b[i]) + i++ + x |= (c & 0x7F) << shift + if c&0x80 == 0 { + return x, i, nil + } + } + return 0, i, errVarintTooLarge +} -- cgit v1.2.3