summaryrefslogtreecommitdiffstats
path: root/ipc/glue/IPCMessageUtils.h
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--ipc/glue/IPCMessageUtils.h238
1 files changed, 238 insertions, 0 deletions
diff --git a/ipc/glue/IPCMessageUtils.h b/ipc/glue/IPCMessageUtils.h
new file mode 100644
index 0000000000..ab9b84e3ea
--- /dev/null
+++ b/ipc/glue/IPCMessageUtils.h
@@ -0,0 +1,238 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 __IPC_GLUE_IPCMESSAGEUTILS_H__
+#define __IPC_GLUE_IPCMESSAGEUTILS_H__
+
+#include <cstdint>
+#include <string>
+#include <type_traits>
+#include "build/build_config.h"
+#include "chrome/common/ipc_message.h"
+#include "chrome/common/ipc_message_utils.h"
+#include "mozilla/ipc/IPCCore.h"
+#include "mozilla/MacroForEach.h"
+
+class PickleIterator;
+
+// XXX Things that are not necessary if moving implementations to the cpp file
+#include "base/string_util.h"
+
+#ifdef _MSC_VER
+# pragma warning(disable : 4800)
+#endif
+
+#if !defined(OS_POSIX)
+// This condition must be kept in sync with the one in
+// ipc_message_utils.h, but this dummy definition of
+// base::FileDescriptor acts as a static assert that we only get one
+// def or the other (or neither, in which case code using
+// FileDescriptor fails to build)
+namespace base {
+struct FileDescriptor {};
+} // namespace base
+#endif
+
+namespace mozilla {
+template <typename...>
+class Variant;
+
+namespace detail {
+template <typename...>
+struct VariantTag;
+}
+} // namespace mozilla
+
+namespace IPC {
+
+/**
+ * A helper class for serializing plain-old data (POD) structures.
+ * The memory representation of the structure is written to and read from
+ * the serialized stream directly, without individual processing of the
+ * structure's members.
+ *
+ * Derive ParamTraits<T> from PlainOldDataSerializer<T> if T is POD.
+ *
+ * Note: For POD structures with enumeration fields, this will not do
+ * validation of the enum values the way serializing the fields
+ * individually would. Prefer serializing the fields individually
+ * in such cases.
+ */
+template <typename T>
+struct PlainOldDataSerializer {
+ static_assert(
+ std::is_trivially_copyable<T>::value,
+ "PlainOldDataSerializer can only be used with trivially copyable types!");
+
+ typedef T paramType;
+
+ static void Write(MessageWriter* aWriter, const paramType& aParam) {
+ aWriter->WriteBytes(&aParam, sizeof(aParam));
+ }
+
+ static bool Read(MessageReader* aReader, paramType* aResult) {
+ return aReader->ReadBytesInto(aResult, sizeof(paramType));
+ }
+};
+
+/**
+ * A helper class for serializing empty structs. Since the struct is empty there
+ * is nothing to write, and a priori we know the result of the read.
+ */
+template <typename T>
+struct EmptyStructSerializer {
+ typedef T paramType;
+
+ static void Write(MessageWriter* aWriter, const paramType& aParam) {}
+
+ static bool Read(MessageReader* aReader, paramType* aResult) {
+ *aResult = {};
+ return true;
+ }
+};
+
+template <>
+struct ParamTraits<int8_t> {
+ typedef int8_t paramType;
+
+ static void Write(MessageWriter* aWriter, const paramType& aParam) {
+ aWriter->WriteBytes(&aParam, sizeof(aParam));
+ }
+
+ static bool Read(MessageReader* aReader, paramType* aResult) {
+ return aReader->ReadBytesInto(aResult, sizeof(*aResult));
+ }
+};
+
+template <>
+struct ParamTraits<uint8_t> {
+ typedef uint8_t paramType;
+
+ static void Write(MessageWriter* aWriter, const paramType& aParam) {
+ aWriter->WriteBytes(&aParam, sizeof(aParam));
+ }
+
+ static bool Read(MessageReader* aReader, paramType* aResult) {
+ return aReader->ReadBytesInto(aResult, sizeof(*aResult));
+ }
+};
+
+#if !defined(OS_POSIX)
+// See above re: keeping definitions in sync
+template <>
+struct ParamTraits<base::FileDescriptor> {
+ typedef base::FileDescriptor paramType;
+ static void Write(MessageWriter* aWriter, const paramType& aParam) {
+ MOZ_CRASH("FileDescriptor isn't meaningful on this platform");
+ }
+ static bool Read(MessageReader* aReader, paramType* aResult) {
+ MOZ_CRASH("FileDescriptor isn't meaningful on this platform");
+ return false;
+ }
+};
+#endif // !defined(OS_POSIX)
+
+template <>
+struct ParamTraits<mozilla::void_t> {
+ typedef mozilla::void_t paramType;
+ static void Write(MessageWriter* aWriter, const paramType& aParam) {}
+ static bool Read(MessageReader* aReader, paramType* aResult) {
+ *aResult = paramType();
+ return true;
+ }
+};
+
+template <>
+struct ParamTraits<mozilla::null_t> {
+ typedef mozilla::null_t paramType;
+ static void Write(MessageWriter* aWriter, const paramType& aParam) {}
+ static bool Read(MessageReader* aReader, paramType* aResult) {
+ *aResult = paramType();
+ return true;
+ }
+};
+
+// Helper class for reading bitfields.
+// If T has bitfields members, derive ParamTraits<T> from BitfieldHelper<T>.
+template <typename ParamType>
+struct BitfieldHelper {
+ // We need this helper because we can't get the address of a bitfield to
+ // pass directly to ReadParam. So instead we read it into a temporary bool
+ // and set the bitfield using a setter function
+ static bool ReadBoolForBitfield(MessageReader* aReader, ParamType* aResult,
+ void (ParamType::*aSetter)(bool)) {
+ bool value;
+ if (ReadParam(aReader, &value)) {
+ (aResult->*aSetter)(value);
+ return true;
+ }
+ return false;
+ }
+};
+
+// A couple of recursive helper functions, allows syntax like:
+// WriteParams(aMsg, aParam.foo, aParam.bar, aParam.baz)
+// ReadParams(aMsg, aIter, aParam.foo, aParam.bar, aParam.baz)
+
+template <typename... Ts>
+static void WriteParams(MessageWriter* aWriter, const Ts&... aArgs) {
+ (WriteParam(aWriter, aArgs), ...);
+}
+
+template <typename... Ts>
+static bool ReadParams(MessageReader* aReader, Ts&... aArgs) {
+ return (ReadParam(aReader, &aArgs) && ...);
+}
+
+// Macros that allow syntax like:
+// DEFINE_IPC_SERIALIZER_WITH_FIELDS(SomeType, member1, member2, member3)
+// Makes sure that serialize/deserialize code do the same members in the same
+// order.
+#define ACCESS_PARAM_FIELD(Field) aParam.Field
+
+#define DEFINE_IPC_SERIALIZER_WITH_FIELDS(Type, ...) \
+ template <> \
+ struct ParamTraits<Type> { \
+ typedef Type paramType; \
+ static void Write(MessageWriter* aWriter, const paramType& aParam) { \
+ WriteParams(aWriter, MOZ_FOR_EACH_SEPARATED(ACCESS_PARAM_FIELD, (, ), \
+ (), (__VA_ARGS__))); \
+ } \
+ \
+ static bool Read(MessageReader* aReader, paramType* aResult) { \
+ paramType& aParam = *aResult; \
+ return ReadParams(aReader, \
+ MOZ_FOR_EACH_SEPARATED(ACCESS_PARAM_FIELD, (, ), (), \
+ (__VA_ARGS__))); \
+ } \
+ };
+
+#define DEFINE_IPC_SERIALIZER_WITHOUT_FIELDS(Type) \
+ template <> \
+ struct ParamTraits<Type> : public EmptyStructSerializer<Type> {};
+
+} /* namespace IPC */
+
+#define DEFINE_IPC_SERIALIZER_WITH_SUPER_CLASS_AND_FIELDS(Type, Super, ...) \
+ template <> \
+ struct ParamTraits<Type> { \
+ typedef Type paramType; \
+ static void Write(MessageWriter* aWriter, const paramType& aParam) { \
+ WriteParam(aWriter, static_cast<const Super&>(aParam)); \
+ WriteParams(aWriter, MOZ_FOR_EACH_SEPARATED(ACCESS_PARAM_FIELD, (, ), \
+ (), (__VA_ARGS__))); \
+ } \
+ \
+ static bool Read(MessageReader* aReader, paramType* aResult) { \
+ paramType& aParam = *aResult; \
+ return ReadParam(aReader, static_cast<Super*>(aResult)) && \
+ ReadParams(aReader, \
+ MOZ_FOR_EACH_SEPARATED(ACCESS_PARAM_FIELD, (, ), (), \
+ (__VA_ARGS__))); \
+ } \
+ };
+
+#endif /* __IPC_GLUE_IPCMESSAGEUTILS_H__ */
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 02:03:31 +0000