1 /*
2   ==============================================================================
3 
4    This file is part of the Water library.
5    Copyright (c) 2016 ROLI Ltd.
6    Copyright (C) 2017 Filipe Coelho <falktx@falktx.com>
7 
8    Permission is granted to use this software under the terms of the ISC license
9    http://www.isc.org/downloads/software-support-policy/isc-license/
10 
11    Permission to use, copy, modify, and/or distribute this software for any
12    purpose with or without fee is hereby granted, provided that the above
13    copyright notice and this permission notice appear in all copies.
14 
15    THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
16    TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
17    FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
18    OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
19    USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
20    TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
21    OF THIS SOFTWARE.
22 
23   ==============================================================================
24 */
25 
26 #ifndef WATER_MEMORYOUTPUTSTREAM_H_INCLUDED
27 #define WATER_MEMORYOUTPUTSTREAM_H_INCLUDED
28 
29 #include "OutputStream.h"
30 #include "../memory/MemoryBlock.h"
31 
32 namespace water {
33 
34 //==============================================================================
35 /**
36     Writes data to an internal memory buffer, which grows as required.
37 
38     The data that was written into the stream can then be accessed later as
39     a contiguous block of memory.
40 */
41 class MemoryOutputStream  : public OutputStream
42 {
43 public:
44     //==============================================================================
45     /** Creates an empty memory stream, ready to be written into.
46         @param initialSize  the intial amount of capacity to allocate for writing into
47     */
48     MemoryOutputStream (size_t initialSize = 256);
49 
50     /** Creates a memory stream for writing into into a pre-existing MemoryBlock object.
51 
52         Note that the destination block will always be larger than the amount of data
53         that has been written to the stream, because the MemoryOutputStream keeps some
54         spare capactity at its end. To trim the block's size down to fit the actual
55         data, call flush(), or delete the MemoryOutputStream.
56 
57         @param memoryBlockToWriteTo             the block into which new data will be written.
58         @param appendToExistingBlockContent     if this is true, the contents of the block will be
59                                                 kept, and new data will be appended to it. If false,
60                                                 the block will be cleared before use
61     */
62     MemoryOutputStream (MemoryBlock& memoryBlockToWriteTo,
63                         bool appendToExistingBlockContent);
64 
65     /** Destructor.
66         This will free any data that was written to it.
67     */
68     ~MemoryOutputStream();
69 
70     //==============================================================================
71     /** Returns a pointer to the data that has been written to the stream.
72         @see getDataSize
73     */
74     const void* getData() const noexcept;
75 
76     /** Returns a pointer to the data that has been written to the stream and releases the buffer pointer.
77         @see getDataSize
78     */
79     void* getDataAndRelease() noexcept;
80 
81     /** Returns the number of bytes of data that have been written to the stream.
82         @see getData
83     */
getDataSize()84     size_t getDataSize() const noexcept                 { return size; }
85 
86     /** Resets the stream, clearing any data that has been written to it so far. */
87     void reset() noexcept;
88 
89     /** Increases the internal storage capacity to be able to contain at least the specified
90         amount of data without needing to be resized.
91     */
92     void preallocate (size_t bytesToPreallocate);
93 
94     /** Appends the utf-8 bytes for a unicode character */
95     bool appendUTF8Char (water_uchar character);
96 
97     /** Returns a String created from the (UTF8) data that has been written to the stream. */
98     String toUTF8() const;
99 
100     /** Attempts to detect the encoding of the data and convert it to a string.
101         @see String::createStringFromData
102     */
103     String toString() const;
104 
105     /** Returns a copy of the stream's data as a memory block. */
106     MemoryBlock getMemoryBlock() const;
107 
108     //==============================================================================
109     /** If the stream is writing to a user-supplied MemoryBlock, this will trim any excess
110         capacity off the block, so that its length matches the amount of actual data that
111         has been written so far.
112     */
113     void flush() override;
114 
115     bool write (const void*, size_t) override;
getPosition()116     int64 getPosition() override                                 { return (int64) position; }
117     bool setPosition (int64) override;
118     int64 writeFromInputStream (InputStream&, int64 maxNumBytesToWrite) override;
119     bool writeRepeatedByte (uint8 byte, size_t numTimesToRepeat) override;
120 
121 private:
122     //==============================================================================
123     MemoryBlock internalBlock;
124     MemoryBlock& blockToUse;
125     size_t position, size;
126     bool usingInternalBlock;
127 
128     void trimExternalBlockSize();
129     char* prepareToWrite (size_t);
130 
131     CARLA_DECLARE_NON_COPY_CLASS (MemoryOutputStream)
132 };
133 
134 /** Copies all the data that has been written to a MemoryOutputStream into another stream. */
135 OutputStream& operator<< (OutputStream& stream, const MemoryOutputStream& streamToRead);
136 
137 }
138 
139 #endif // WATER_MEMORYOUTPUTSTREAM_H_INCLUDED
140