Parcel.h revision 70081a1511955f53bd0ed7f2aec9a1bf09f0f379 
1/*
2 * Copyright (C) 2005 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_PARCEL_H
18#define ANDROID_PARCEL_H
19
20#include <cutils/native_handle.h>
21#include <utils/Errors.h>
22#include <utils/RefBase.h>
23#include <utils/String16.h>
24#include <utils/Vector.h>
25
26// ---------------------------------------------------------------------------
27namespace android {
28
29class Flattenable;
30class IBinder;
31class IPCThreadState;
32class ProcessState;
33class String8;
34class TextOutput;
35
36struct flat_binder_object;  // defined in support_p/binder_module.h
37
38class Parcel
39{
40public:
41                        Parcel();
42                        ~Parcel();
43
44    const uint8_t*      data() const;
45    size_t              dataSize() const;
46    size_t              dataAvail() const;
47    size_t              dataPosition() const;
48    size_t              dataCapacity() const;
49
50    status_t            setDataSize(size_t size);
51    void                setDataPosition(size_t pos) const;
52    status_t            setDataCapacity(size_t size);
53
54    status_t            setData(const uint8_t* buffer, size_t len);
55
56    status_t            appendFrom(Parcel *parcel, size_t start, size_t len);
57
58    bool                hasFileDescriptors() const;
59
60    // Writes the RPC header.
61    status_t            writeInterfaceToken(const String16& interface);
62
63    // Parses the RPC header, returning true if the interface name
64    // in the header matches the expected interface from the caller.
65    //
66    // Additionally, enforceInterface does part of the work of
67    // propagating the StrictMode policy mask, populating the current
68    // IPCThreadState, which as an optimization may optionally be
69    // passed in.
70    bool                enforceInterface(const String16& interface,
71                                         IPCThreadState* threadState = NULL) const;
72    bool                checkInterface(IBinder*) const;
73
74    void                freeData();
75
76    const size_t*       objects() const;
77    size_t              objectsCount() const;
78
79    status_t            errorCheck() const;
80    void                setError(status_t err);
81
82    status_t            write(const void* data, size_t len);
83    void*               writeInplace(size_t len);
84    status_t            writeUnpadded(const void* data, size_t len);
85    status_t            writeInt32(int32_t val);
86    status_t            writeInt64(int64_t val);
87    status_t            writeFloat(float val);
88    status_t            writeDouble(double val);
89    status_t            writeIntPtr(intptr_t val);
90    status_t            writeCString(const char* str);
91    status_t            writeString8(const String8& str);
92    status_t            writeString16(const String16& str);
93    status_t            writeString16(const char16_t* str, size_t len);
94    status_t            writeStrongBinder(const sp<IBinder>& val);
95    status_t            writeWeakBinder(const wp<IBinder>& val);
96    status_t            write(const Flattenable& val);
97
98    // Place a native_handle into the parcel (the native_handle's file-
99    // descriptors are dup'ed, so it is safe to delete the native_handle
100    // when this function returns).
101    // Doesn't take ownership of the native_handle.
102    status_t            writeNativeHandle(const native_handle* handle);
103
104    // Place a file descriptor into the parcel.  The given fd must remain
105    // valid for the lifetime of the parcel.
106    status_t            writeFileDescriptor(int fd);
107
108    // Place a file descriptor into the parcel.  A dup of the fd is made, which
109    // will be closed once the parcel is destroyed.
110    status_t            writeDupFileDescriptor(int fd);
111
112    status_t            writeObject(const flat_binder_object& val, bool nullMetaData);
113
114    // Like Parcel.java's writeNoException().  Just writes a zero int32.
115    // Currently the native implementation doesn't do any of the StrictMode
116    // stack gathering and serialization that the Java implementation does.
117    status_t            writeNoException();
118
119    void                remove(size_t start, size_t amt);
120
121    status_t            read(void* outData, size_t len) const;
122    const void*         readInplace(size_t len) const;
123    int32_t             readInt32() const;
124    status_t            readInt32(int32_t *pArg) const;
125    int64_t             readInt64() const;
126    status_t            readInt64(int64_t *pArg) const;
127    float               readFloat() const;
128    status_t            readFloat(float *pArg) const;
129    double              readDouble() const;
130    status_t            readDouble(double *pArg) const;
131    intptr_t            readIntPtr() const;
132    status_t            readIntPtr(intptr_t *pArg) const;
133
134    const char*         readCString() const;
135    String8             readString8() const;
136    String16            readString16() const;
137    const char16_t*     readString16Inplace(size_t* outLen) const;
138    sp<IBinder>         readStrongBinder() const;
139    wp<IBinder>         readWeakBinder() const;
140    status_t            read(Flattenable& val) const;
141
142    // Like Parcel.java's readExceptionCode().  Reads the first int32
143    // off of a Parcel's header, returning 0 or the negative error
144    // code on exceptions, but also deals with skipping over rich
145    // response headers.  Callers should use this to read & parse the
146    // response headers rather than doing it by hand.
147    int32_t             readExceptionCode() const;
148
149    // Retrieve native_handle from the parcel. This returns a copy of the
150    // parcel's native_handle (the caller takes ownership). The caller
151    // must free the native_handle with native_handle_close() and
152    // native_handle_delete().
153    native_handle*     readNativeHandle() const;
154
155
156    // Retrieve a file descriptor from the parcel.  This returns the raw fd
157    // in the parcel, which you do not own -- use dup() to get your own copy.
158    int                 readFileDescriptor() const;
159
160    const flat_binder_object* readObject(bool nullMetaData) const;
161
162    // Explicitly close all file descriptors in the parcel.
163    void                closeFileDescriptors();
164
165    typedef void        (*release_func)(Parcel* parcel,
166                                        const uint8_t* data, size_t dataSize,
167                                        const size_t* objects, size_t objectsSize,
168                                        void* cookie);
169
170    const uint8_t*      ipcData() const;
171    size_t              ipcDataSize() const;
172    const size_t*       ipcObjects() const;
173    size_t              ipcObjectsCount() const;
174    void                ipcSetDataReference(const uint8_t* data, size_t dataSize,
175                                            const size_t* objects, size_t objectsCount,
176                                            release_func relFunc, void* relCookie);
177
178    void                print(TextOutput& to, uint32_t flags = 0) const;
179
180private:
181                        Parcel(const Parcel& o);
182    Parcel&             operator=(const Parcel& o);
183
184    status_t            finishWrite(size_t len);
185    void                releaseObjects();
186    void                acquireObjects();
187    status_t            growData(size_t len);
188    status_t            restartWrite(size_t desired);
189    status_t            continueWrite(size_t desired);
190    void                freeDataNoInit();
191    void                initState();
192    void                scanForFds() const;
193
194    template<class T>
195    status_t            readAligned(T *pArg) const;
196
197    template<class T>   T readAligned() const;
198
199    template<class T>
200    status_t            writeAligned(T val);
201
202    status_t            mError;
203    uint8_t*            mData;
204    size_t              mDataSize;
205    size_t              mDataCapacity;
206    mutable size_t      mDataPos;
207    size_t*             mObjects;
208    size_t              mObjectsSize;
209    size_t              mObjectsCapacity;
210    mutable size_t      mNextObjectHint;
211
212    mutable bool        mFdsKnown;
213    mutable bool        mHasFds;
214
215    release_func        mOwner;
216    void*               mOwnerCookie;
217};
218
219// ---------------------------------------------------------------------------
220
221inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel)
222{
223    parcel.print(to);
224    return to;
225}
226
227// ---------------------------------------------------------------------------
228
229// Generic acquire and release of objects.
230void acquire_object(const sp<ProcessState>& proc,
231                    const flat_binder_object& obj, const void* who);
232void release_object(const sp<ProcessState>& proc,
233                    const flat_binder_object& obj, const void* who);
234
235void flatten_binder(const sp<ProcessState>& proc,
236                    const sp<IBinder>& binder, flat_binder_object* out);
237void flatten_binder(const sp<ProcessState>& proc,
238                    const wp<IBinder>& binder, flat_binder_object* out);
239status_t unflatten_binder(const sp<ProcessState>& proc,
240                          const flat_binder_object& flat, sp<IBinder>* out);
241status_t unflatten_binder(const sp<ProcessState>& proc,
242                          const flat_binder_object& flat, wp<IBinder>* out);
243
244}; // namespace android
245
246// ---------------------------------------------------------------------------
247
248#endif // ANDROID_PARCEL_H
249