1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/core/SkData.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,148 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2011 Google Inc.
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +
1.13 +
1.14 +#ifndef SkData_DEFINED
1.15 +#define SkData_DEFINED
1.16 +
1.17 +#include "SkRefCnt.h"
1.18 +
1.19 +struct SkFILE;
1.20 +
1.21 +/**
1.22 + * SkData holds an immutable data buffer. Not only is the data immutable,
1.23 + * but the actual ptr that is returned (by data() or bytes()) is guaranteed
1.24 + * to always be the same for the life of this instance.
1.25 + */
1.26 +class SK_API SkData : public SkRefCnt {
1.27 +public:
1.28 + SK_DECLARE_INST_COUNT(SkData)
1.29 +
1.30 + /**
1.31 + * Returns the number of bytes stored.
1.32 + */
1.33 + size_t size() const { return fSize; }
1.34 +
1.35 + bool isEmpty() const { return 0 == fSize; }
1.36 +
1.37 + /**
1.38 + * Returns the ptr to the data.
1.39 + */
1.40 + const void* data() const { return fPtr; }
1.41 +
1.42 + /**
1.43 + * Like data(), returns a read-only ptr into the data, but in this case
1.44 + * it is cast to uint8_t*, to make it easy to add an offset to it.
1.45 + */
1.46 + const uint8_t* bytes() const {
1.47 + return reinterpret_cast<const uint8_t*>(fPtr);
1.48 + }
1.49 +
1.50 + /**
1.51 + * Helper to copy a range of the data into a caller-provided buffer.
1.52 + * Returns the actual number of bytes copied, after clamping offset and
1.53 + * length to the size of the data. If buffer is NULL, it is ignored, and
1.54 + * only the computed number of bytes is returned.
1.55 + */
1.56 + size_t copyRange(size_t offset, size_t length, void* buffer) const;
1.57 +
1.58 + /**
1.59 + * Returns true if these two objects have the same length and contents,
1.60 + * effectively returning 0 == memcmp(...)
1.61 + */
1.62 + bool equals(const SkData* other) const;
1.63 +
1.64 + /**
1.65 + * Function that, if provided, will be called when the SkData goes out
1.66 + * of scope, allowing for custom allocation/freeing of the data.
1.67 + */
1.68 + typedef void (*ReleaseProc)(const void* ptr, size_t length, void* context);
1.69 +
1.70 + /**
1.71 + * Create a new dataref by copying the specified data
1.72 + */
1.73 + static SkData* NewWithCopy(const void* data, size_t length);
1.74 +
1.75 + /**
1.76 + * Create a new dataref by copying the specified c-string
1.77 + * (a null-terminated array of bytes). The returned SkData will have size()
1.78 + * equal to strlen(cstr) + 1. If cstr is NULL, it will be treated the same
1.79 + * as "".
1.80 + */
1.81 + static SkData* NewWithCString(const char cstr[]);
1.82 +
1.83 + /**
1.84 + * Create a new dataref, taking the data ptr as is, and using the
1.85 + * releaseproc to free it. The proc may be NULL.
1.86 + */
1.87 + static SkData* NewWithProc(const void* data, size_t length,
1.88 + ReleaseProc proc, void* context);
1.89 +
1.90 + /**
1.91 + * Create a new dataref from a pointer allocated by malloc. The Data object
1.92 + * takes ownership of that allocation, and will handling calling sk_free.
1.93 + */
1.94 + static SkData* NewFromMalloc(const void* data, size_t length);
1.95 +
1.96 + /**
1.97 + * Create a new dataref the file with the specified path.
1.98 + * If the file cannot be opened, this returns NULL.
1.99 + */
1.100 + static SkData* NewFromFileName(const char path[]);
1.101 +
1.102 + /**
1.103 + * Create a new dataref from a SkFILE.
1.104 + * This does not take ownership of the SkFILE, nor close it.
1.105 + * The caller is free to close the SkFILE at its convenience.
1.106 + * The SkFILE must be open for reading only.
1.107 + * Returns NULL on failure.
1.108 + */
1.109 + static SkData* NewFromFILE(SkFILE* f);
1.110 +
1.111 + /**
1.112 + * Create a new dataref from a file descriptor.
1.113 + * This does not take ownership of the file descriptor, nor close it.
1.114 + * The caller is free to close the file descriptor at its convenience.
1.115 + * The file descriptor must be open for reading only.
1.116 + * Returns NULL on failure.
1.117 + */
1.118 + static SkData* NewFromFD(int fd);
1.119 +
1.120 + /**
1.121 + * Create a new dataref using a subset of the data in the specified
1.122 + * src dataref.
1.123 + */
1.124 + static SkData* NewSubset(const SkData* src, size_t offset, size_t length);
1.125 +
1.126 + /**
1.127 + * Returns a new empty dataref (or a reference to a shared empty dataref).
1.128 + * New or shared, the caller must see that unref() is eventually called.
1.129 + */
1.130 + static SkData* NewEmpty();
1.131 +
1.132 +private:
1.133 + ReleaseProc fReleaseProc;
1.134 + void* fReleaseProcContext;
1.135 +
1.136 + const void* fPtr;
1.137 + size_t fSize;
1.138 +
1.139 + SkData(const void* ptr, size_t size, ReleaseProc, void* context);
1.140 + virtual ~SkData();
1.141 +
1.142 + // Called the first time someone calls NewEmpty to initialize the singleton.
1.143 + static void NewEmptyImpl(int/*unused*/);
1.144 +
1.145 + typedef SkRefCnt INHERITED;
1.146 +};
1.147 +
1.148 +/** Typedef of SkAutoTUnref<SkData> for automatically unref-ing a SkData. */
1.149 +typedef SkAutoTUnref<SkData> SkAutoDataUnref;
1.150 +
1.151 +#endif
