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      1 /*
      2  * Copyright (C) 2012 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_CLIENT_CAMERA2_CAMERAMETADATA_CPP
     18 #define ANDROID_CLIENT_CAMERA2_CAMERAMETADATA_CPP
     19 
     20 #include "system/camera_metadata.h"
     21 
     22 #include <utils/String8.h>
     23 #include <utils/Vector.h>
     24 #include <binder/Parcelable.h>
     25 
     26 namespace android {
     27 
     28 class VendorTagDescriptor;
     29 
     30 /**
     31  * A convenience wrapper around the C-based camera_metadata_t library.
     32  */
     33 class CameraMetadata: public Parcelable {
     34   public:
     35     /** Creates an empty object; best used when expecting to acquire contents
     36      * from elsewhere */
     37     CameraMetadata();
     38     /** Creates an object with space for entryCapacity entries, with
     39      * dataCapacity extra storage */
     40     CameraMetadata(size_t entryCapacity, size_t dataCapacity = 10);
     41 
     42     ~CameraMetadata();
     43 
     44     /** Takes ownership of passed-in buffer */
     45     CameraMetadata(camera_metadata_t *buffer);
     46     /** Clones the metadata */
     47     CameraMetadata(const CameraMetadata &other);
     48 
     49     /**
     50      * Assignment clones metadata buffer.
     51      */
     52     CameraMetadata &operator=(const CameraMetadata &other);
     53     CameraMetadata &operator=(const camera_metadata_t *buffer);
     54 
     55     /**
     56      * Get reference to the underlying metadata buffer. Ownership remains with
     57      * the CameraMetadata object, but non-const CameraMetadata methods will not
     58      * work until unlock() is called. Note that the lock has nothing to do with
     59      * thread-safety, it simply prevents the camera_metadata_t pointer returned
     60      * here from being accidentally invalidated by CameraMetadata operations.
     61      */
     62     const camera_metadata_t* getAndLock() const;
     63 
     64     /**
     65      * Unlock the CameraMetadata for use again. After this unlock, the pointer
     66      * given from getAndLock() may no longer be used. The pointer passed out
     67      * from getAndLock must be provided to guarantee that the right object is
     68      * being unlocked.
     69      */
     70     status_t unlock(const camera_metadata_t *buffer) const;
     71 
     72     /**
     73      * Release a raw metadata buffer to the caller. After this call,
     74      * CameraMetadata no longer references the buffer, and the caller takes
     75      * responsibility for freeing the raw metadata buffer (using
     76      * free_camera_metadata()), or for handing it to another CameraMetadata
     77      * instance.
     78      */
     79     camera_metadata_t* release();
     80 
     81     /**
     82      * Clear the metadata buffer and free all storage used by it
     83      */
     84     void clear();
     85 
     86     /**
     87      * Acquire a raw metadata buffer from the caller. After this call,
     88      * the caller no longer owns the raw buffer, and must not free or manipulate it.
     89      * If CameraMetadata already contains metadata, it is freed.
     90      */
     91     void acquire(camera_metadata_t* buffer);
     92 
     93     /**
     94      * Acquires raw buffer from other CameraMetadata object. After the call, the argument
     95      * object no longer has any metadata.
     96      */
     97     void acquire(CameraMetadata &other);
     98 
     99     /**
    100      * Append metadata from another CameraMetadata object.
    101      */
    102     status_t append(const CameraMetadata &other);
    103 
    104     /**
    105      * Append metadata from a raw camera_metadata buffer
    106      */
    107     status_t append(const camera_metadata* other);
    108 
    109     /**
    110      * Number of metadata entries.
    111      */
    112     size_t entryCount() const;
    113 
    114     /**
    115      * Is the buffer empty (no entires)
    116      */
    117     bool isEmpty() const;
    118 
    119     /**
    120      * Sort metadata buffer for faster find
    121      */
    122     status_t sort();
    123 
    124     /**
    125      * Update metadata entry. Will create entry if it doesn't exist already, and
    126      * will reallocate the buffer if insufficient space exists. Overloaded for
    127      * the various types of valid data.
    128      */
    129     status_t update(uint32_t tag,
    130             const uint8_t *data, size_t data_count);
    131     status_t update(uint32_t tag,
    132             const int32_t *data, size_t data_count);
    133     status_t update(uint32_t tag,
    134             const float *data, size_t data_count);
    135     status_t update(uint32_t tag,
    136             const int64_t *data, size_t data_count);
    137     status_t update(uint32_t tag,
    138             const double *data, size_t data_count);
    139     status_t update(uint32_t tag,
    140             const camera_metadata_rational_t *data, size_t data_count);
    141     status_t update(uint32_t tag,
    142             const String8 &string);
    143     status_t update(const camera_metadata_ro_entry &entry);
    144 
    145 
    146     template<typename T>
    147     status_t update(uint32_t tag, Vector<T> data) {
    148         return update(tag, data.array(), data.size());
    149     }
    150 
    151     /**
    152      * Check if a metadata entry exists for a given tag id
    153      *
    154      */
    155     bool exists(uint32_t tag) const;
    156 
    157     /**
    158      * Get metadata entry by tag id
    159      */
    160     camera_metadata_entry find(uint32_t tag);
    161 
    162     /**
    163      * Get metadata entry by tag id, with no editing
    164      */
    165     camera_metadata_ro_entry find(uint32_t tag) const;
    166 
    167     /**
    168      * Delete metadata entry by tag
    169      */
    170     status_t erase(uint32_t tag);
    171 
    172     /**
    173      * Swap the underlying camera metadata between this and the other
    174      * metadata object.
    175      */
    176     void swap(CameraMetadata &other);
    177 
    178     /**
    179      * Dump contents into FD for debugging. The verbosity levels are
    180      * 0: Tag entry information only, no data values
    181      * 1: Level 0 plus at most 16 data values per entry
    182      * 2: All information
    183      *
    184      * The indentation parameter sets the number of spaces to add to the start
    185      * each line of output.
    186      */
    187     void dump(int fd, int verbosity = 1, int indentation = 0) const;
    188 
    189     /**
    190      * Serialization over Binder
    191      */
    192 
    193     // Metadata object is unchanged when reading from parcel fails.
    194     virtual status_t readFromParcel(const Parcel *parcel) override;
    195     virtual status_t writeToParcel(Parcel *parcel) const override;
    196 
    197     /**
    198       * Caller becomes the owner of the new metadata
    199       * 'const Parcel' doesnt prevent us from calling the read functions.
    200       *  which is interesting since it changes the internal state
    201       *
    202       * NULL can be returned when no metadata was sent, OR if there was an issue
    203       * unpacking the serialized data (i.e. bad parcel or invalid structure).
    204       */
    205     static status_t readFromParcel(const Parcel &parcel,
    206                                    camera_metadata_t** out);
    207     /**
    208       * Caller retains ownership of metadata
    209       * - Write 2 (int32 + blob) args in the current position
    210       */
    211     static status_t writeToParcel(Parcel &parcel,
    212                                   const camera_metadata_t* metadata);
    213 
    214     /**
    215      * Find tag id for a given tag name, also checking vendor tags if available.
    216      * On success, returns OK and writes the tag id into tag.
    217      *
    218      * This is a slow method.
    219      */
    220     static status_t getTagFromName(const char *name,
    221             const VendorTagDescriptor* vTags, uint32_t *tag);
    222 
    223   private:
    224     camera_metadata_t *mBuffer;
    225     mutable bool       mLocked;
    226 
    227     /**
    228      * Check if tag has a given type
    229      */
    230     status_t checkType(uint32_t tag, uint8_t expectedType);
    231 
    232     /**
    233      * Base update entry method
    234      */
    235     status_t updateImpl(uint32_t tag, const void *data, size_t data_count);
    236 
    237     /**
    238      * Resize metadata buffer if needed by reallocating it and copying it over.
    239      */
    240     status_t resizeIfNeeded(size_t extraEntries, size_t extraData);
    241 
    242 };
    243 
    244 namespace hardware {
    245 namespace camera2 {
    246 namespace impl {
    247 using ::android::CameraMetadata;
    248 typedef CameraMetadata CameraMetadataNative;
    249 }
    250 }
    251 }
    252 
    253 } // namespace android
    254 
    255 #endif
    256