Parcel.h revision 8938ed2c8e906fc332301b64787728d4d34da571 
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(const Parcel *parcel,
57                                   size_t start, size_t len);
58
59    bool                setAllowFds(bool allowFds);
60
61    bool                hasFileDescriptors() const;
62
63    // Writes the RPC header.
64    status_t            writeInterfaceToken(const String16& interface);
65
66    // Parses the RPC header, returning true if the interface name
67    // in the header matches the expected interface from the caller.
68    //
69    // Additionally, enforceInterface does part of the work of
70    // propagating the StrictMode policy mask, populating the current
71    // IPCThreadState, which as an optimization may optionally be
72    // passed in.
73    bool                enforceInterface(const String16& interface,
74                                         IPCThreadState* threadState = NULL) const;
75    bool                checkInterface(IBinder*) const;
76
77    void                freeData();
78
79    const size_t*       objects() const;
80    size_t              objectsCount() const;
81
82    status_t            errorCheck() const;
83    void                setError(status_t err);
84
85    status_t            write(const void* data, size_t len);
86    void*               writeInplace(size_t len);
87    status_t            writeUnpadded(const void* data, size_t len);
88    status_t            writeInt32(int32_t val);
89    status_t            writeInt64(int64_t val);
90    status_t            writeFloat(float val);
91    status_t            writeDouble(double val);
92    status_t            writeIntPtr(intptr_t val);
93    status_t            writeCString(const char* str);
94    status_t            writeString8(const String8& str);
95    status_t            writeString16(const String16& str);
96    status_t            writeString16(const char16_t* str, size_t len);
97    status_t            writeStrongBinder(const sp<IBinder>& val);
98    status_t            writeWeakBinder(const wp<IBinder>& val);
99    status_t            write(const Flattenable& val);
100
101    // Place a native_handle into the parcel (the native_handle's file-
102    // descriptors are dup'ed, so it is safe to delete the native_handle
103    // when this function returns).
104    // Doesn't take ownership of the native_handle.
105    status_t            writeNativeHandle(const native_handle* handle);
106
107    // Place a file descriptor into the parcel.  The given fd must remain
108    // valid for the lifetime of the parcel.
109    status_t            writeFileDescriptor(int fd);
110
111    // Place a file descriptor into the parcel.  A dup of the fd is made, which
112    // will be closed once the parcel is destroyed.
113    status_t            writeDupFileDescriptor(int fd);
114
115    status_t            writeObject(const flat_binder_object& val, bool nullMetaData);
116
117    // Like Parcel.java's writeNoException().  Just writes a zero int32.
118    // Currently the native implementation doesn't do any of the StrictMode
119    // stack gathering and serialization that the Java implementation does.
120    status_t            writeNoException();
121
122    void                remove(size_t start, size_t amt);
123
124    status_t            read(void* outData, size_t len) const;
125    const void*         readInplace(size_t len) const;
126    int32_t             readInt32() const;
127    status_t            readInt32(int32_t *pArg) const;
128    int64_t             readInt64() const;
129    status_t            readInt64(int64_t *pArg) const;
130    float               readFloat() const;
131    status_t            readFloat(float *pArg) const;
132    double              readDouble() const;
133    status_t            readDouble(double *pArg) const;
134    intptr_t            readIntPtr() const;
135    status_t            readIntPtr(intptr_t *pArg) const;
136
137    const char*         readCString() const;
138    String8             readString8() const;
139    String16            readString16() const;
140    const char16_t*     readString16Inplace(size_t* outLen) const;
141    sp<IBinder>         readStrongBinder() const;
142    wp<IBinder>         readWeakBinder() const;
143    status_t            read(Flattenable& val) const;
144
145    // Like Parcel.java's readExceptionCode().  Reads the first int32
146    // off of a Parcel's header, returning 0 or the negative error
147    // code on exceptions, but also deals with skipping over rich
148    // response headers.  Callers should use this to read & parse the
149    // response headers rather than doing it by hand.
150    int32_t             readExceptionCode() const;
151
152    // Retrieve native_handle from the parcel. This returns a copy of the
153    // parcel's native_handle (the caller takes ownership). The caller
154    // must free the native_handle with native_handle_close() and
155    // native_handle_delete().
156    native_handle*     readNativeHandle() const;
157
158
159    // Retrieve a file descriptor from the parcel.  This returns the raw fd
160    // in the parcel, which you do not own -- use dup() to get your own copy.
161    int                 readFileDescriptor() const;
162
163    const flat_binder_object* readObject(bool nullMetaData) const;
164
165    // Explicitly close all file descriptors in the parcel.
166    void                closeFileDescriptors();
167
168    typedef void        (*release_func)(Parcel* parcel,
169                                        const uint8_t* data, size_t dataSize,
170                                        const size_t* objects, size_t objectsSize,
171                                        void* cookie);
172
173    const uint8_t*      ipcData() const;
174    size_t              ipcDataSize() const;
175    const size_t*       ipcObjects() const;
176    size_t              ipcObjectsCount() const;
177    void                ipcSetDataReference(const uint8_t* data, size_t dataSize,
178                                            const size_t* objects, size_t objectsCount,
179                                            release_func relFunc, void* relCookie);
180
181    void                print(TextOutput& to, uint32_t flags = 0) const;
182
183private:
184                        Parcel(const Parcel& o);
185    Parcel&             operator=(const Parcel& o);
186
187    status_t            finishWrite(size_t len);
188    void                releaseObjects();
189    void                acquireObjects();
190    status_t            growData(size_t len);
191    status_t            restartWrite(size_t desired);
192    status_t            continueWrite(size_t desired);
193    void                freeDataNoInit();
194    void                initState();
195    void                scanForFds() const;
196
197    template<class T>
198    status_t            readAligned(T *pArg) const;
199
200    template<class T>   T readAligned() const;
201
202    template<class T>
203    status_t            writeAligned(T val);
204
205    status_t            mError;
206    uint8_t*            mData;
207    size_t              mDataSize;
208    size_t              mDataCapacity;
209    mutable size_t      mDataPos;
210    size_t*             mObjects;
211    size_t              mObjectsSize;
212    size_t              mObjectsCapacity;
213    mutable size_t      mNextObjectHint;
214
215    mutable bool        mFdsKnown;
216    mutable bool        mHasFds;
217    bool                mAllowFds;
218
219    release_func        mOwner;
220    void*               mOwnerCookie;
221};
222
223// ---------------------------------------------------------------------------
224
225inline TextOutput& operator<<(TextOutput& to, const Parcel& parcel)
226{
227    parcel.print(to);
228    return to;
229}
230
231// ---------------------------------------------------------------------------
232
233// Generic acquire and release of objects.
234void acquire_object(const sp<ProcessState>& proc,
235                    const flat_binder_object& obj, const void* who);
236void release_object(const sp<ProcessState>& proc,
237                    const flat_binder_object& obj, const void* who);
238
239void flatten_binder(const sp<ProcessState>& proc,
240                    const sp<IBinder>& binder, flat_binder_object* out);
241void flatten_binder(const sp<ProcessState>& proc,
242                    const wp<IBinder>& binder, flat_binder_object* out);
243status_t unflatten_binder(const sp<ProcessState>& proc,
244                          const flat_binder_object& flat, sp<IBinder>* out);
245status_t unflatten_binder(const sp<ProcessState>& proc,
246                          const flat_binder_object& flat, wp<IBinder>* out);
247
248}; // namespace android
249
250// ---------------------------------------------------------------------------
251
252#endif // ANDROID_PARCEL_H
253