The Tor Browser: comparison js/src/vm/Xdr.h

--1:000000000000
+:3656f1229bc8
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+* vim: set ts=8 sts=4 et sw=4 tw=99:
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef vm_Xdr_h
+#define vm_Xdr_h
+#include "mozilla/Endian.h"
+#include "mozilla/TypeTraits.h"
+#include "jsatom.h"
+namespace js {
+/*
+* Bytecode version number. Increment the subtrahend whenever JS bytecode
+* changes incompatibly.
+*
+* This version number is XDR'd near the front of xdr bytecode and
+* aborts deserialization if there is a mismatch between the current
+* and saved versions. If deserialization fails, the data should be
+* invalidated if possible.
+*/
+static const uint32_t XDR_BYTECODE_VERSION = uint32_t(0xb973c0de - 172);
+class XDRBuffer {
+public:
+XDRBuffer(JSContext *cx)
+: context(cx), base(nullptr), cursor(nullptr), limit(nullptr) { }
+JSContext *cx() const {
+return context;
+}
+void *getData(uint32_t *lengthp) const {
+JS_ASSERT(size_t(cursor - base) <= size_t(UINT32_MAX));
+*lengthp = uint32_t(cursor - base);
+return base;
+}
+void setData(const void *data, uint32_t length) {
+base = static_cast<uint8_t *>(const_cast<void *>(data));
+cursor = base;
+limit = base + length;
+}
+const uint8_t *read(size_t n) {
+JS_ASSERT(n <= size_t(limit - cursor));
+uint8_t *ptr = cursor;
+cursor += n;
+return ptr;
+}
+const char *readCString() {
+char *ptr = reinterpret_cast<char *>(cursor);
+cursor = reinterpret_cast<uint8_t *>(strchr(ptr, '\0')) + 1;
+JS_ASSERT(base < cursor);
+JS_ASSERT(cursor <= limit);
+return ptr;
+}
+uint8_t *write(size_t n) {
+if (n > size_t(limit - cursor)) {
+if (!grow(n))
+return nullptr;
+}
+uint8_t *ptr = cursor;
+cursor += n;
+return ptr;
+}
+static bool isUint32Overflow(size_t n) {
+return size_t(-1) > size_t(UINT32_MAX) && n > size_t(UINT32_MAX);
+}
+void freeBuffer();
+private:
+bool grow(size_t n);
+JSContext   *const context;
+uint8_t     *base;
+uint8_t     *cursor;
+uint8_t     *limit;
+};
+/*
+* XDR serialization state.  All data is encoded in little endian.
+*/
+template <XDRMode mode>
+class XDRState {
+public:
+XDRBuffer buf;
+protected:
+JSPrincipals *originPrincipals_;
+XDRState(JSContext *cx)
+: buf(cx), originPrincipals_(nullptr) {
+}
+public:
+JSContext *cx() const {
+return buf.cx();
+}
+JSPrincipals *originPrincipals() const {
+return originPrincipals_;
+}
+bool codeUint8(uint8_t *n) {
+if (mode == XDR_ENCODE) {
+uint8_t *ptr = buf.write(sizeof *n);
+if (!ptr)
+return false;
+*ptr = *n;
+} else {
+*n = *buf.read(sizeof *n);
+}
+return true;
+}
+bool codeUint16(uint16_t *n) {
+if (mode == XDR_ENCODE) {
+uint8_t *ptr = buf.write(sizeof *n);
+if (!ptr)
+return false;
+mozilla::LittleEndian::writeUint16(ptr, *n);
+} else {
+const uint8_t *ptr = buf.read(sizeof *n);
+*n = mozilla::LittleEndian::readUint16(ptr);
+}
+return true;
+}
+bool codeUint32(uint32_t *n) {
+if (mode == XDR_ENCODE) {
+uint8_t *ptr = buf.write(sizeof *n);
+if (!ptr)
+return false;
+mozilla::LittleEndian::writeUint32(ptr, *n);
+} else {
+const uint8_t *ptr = buf.read(sizeof *n);
+*n = mozilla::LittleEndian::readUint32(ptr);
+}
+return true;
+}
+bool codeUint64(uint64_t *n) {
+if (mode == XDR_ENCODE) {
+uint8_t *ptr = buf.write(sizeof(*n));
+if (!ptr)
+return false;
+mozilla::LittleEndian::writeUint64(ptr, *n);
+} else {
+const uint8_t *ptr = buf.read(sizeof(*n));
+*n = mozilla::LittleEndian::readUint64(ptr);
+}
+return true;
+}
+/*
+* Use SFINAE to refuse any specialization which is not an enum.  Uses of
+* this function do not have to specialize the type of the enumerated field
+* as C++ will extract the parameterized from the argument list.
+*/
+template <typename T>
+bool codeEnum32(T *val, typename mozilla::EnableIf<mozilla::IsEnum<T>::value, T>::Type * = NULL)
+{
+uint32_t tmp;
+if (mode == XDR_ENCODE)
+tmp = *val;
+if (!codeUint32(&tmp))
+return false;
+if (mode == XDR_DECODE)
+*val = T(tmp);
+return true;
+}
+bool codeDouble(double *dp) {
+union DoublePun {
+double d;
+uint64_t u;
+} pun;
+if (mode == XDR_ENCODE)
+pun.d = *dp;
+if (!codeUint64(&pun.u))
+return false;
+if (mode == XDR_DECODE)
+*dp = pun.d;
+return true;
+}
+bool codeBytes(void *bytes, size_t len) {
+if (mode == XDR_ENCODE) {
+uint8_t *ptr = buf.write(len);
+if (!ptr)
+return false;
+memcpy(ptr, bytes, len);
+} else {
+memcpy(bytes, buf.read(len), len);
+}
+return true;
+}
+/*
+* During encoding the string is written into the buffer together with its
+* terminating '\0'. During decoding the method returns a pointer into the
+* decoding buffer and the caller must copy the string if it will outlive
+* the decoding buffer.
+*/
+bool codeCString(const char **sp) {
+if (mode == XDR_ENCODE) {
+size_t n = strlen(*sp) + 1;
+uint8_t *ptr = buf.write(n);
+if (!ptr)
+return false;
+memcpy(ptr, *sp, n);
+} else {
+*sp = buf.readCString();
+}
+return true;
+}
+bool codeChars(jschar *chars, size_t nchars);
+bool codeFunction(JS::MutableHandleObject objp);
+bool codeScript(MutableHandleScript scriptp);
+bool codeConstValue(MutableHandleValue vp);
+};
+class XDREncoder : public XDRState<XDR_ENCODE> {
+public:
+XDREncoder(JSContext *cx)
+: XDRState<XDR_ENCODE>(cx) {
+}
+~XDREncoder() {
+buf.freeBuffer();
+}
+const void *getData(uint32_t *lengthp) const {
+return buf.getData(lengthp);
+}
+void *forgetData(uint32_t *lengthp) {
+void *data = buf.getData(lengthp);
+buf.setData(nullptr, 0);
+return data;
+}
+};
+class XDRDecoder : public XDRState<XDR_DECODE> {
+public:
+XDRDecoder(JSContext *cx, const void *data, uint32_t length,
+JSPrincipals *originPrincipals);
+};
+} /* namespace js */
+#endif /* vm_Xdr_h */

The Tor Browser / file comparison

comparison: js/src/vm/Xdr.h

js/src/vm/Xdr.h