Ticket #553: MemoryConduitEnhanced.d
| File MemoryConduitEnhanced.d, 2.9 kB (added by Nietsnie, 1 year ago) |
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Example MemoryConduit? with the above implementation |
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| 1 | module tango.io.MemoryConduitEnhanced; |
| 2 | |
| 3 | public import tango.io.MemoryConduit; |
| 4 | public import tango.io.model.IConduit; |
| 5 | |
| 6 | class MemoryConduitEnhanced : Conduit, IConduit.Seek |
| 7 | { |
| 8 | |
| 9 | private void[] content; |
| 10 | private long _pos = 0; |
| 11 | |
| 12 | /*********************************************************************** |
| 13 | |
| 14 | Return a preferred size for buffering conduit I/O |
| 15 | |
| 16 | ***********************************************************************/ |
| 17 | |
| 18 | uint bufferSize () |
| 19 | { |
| 20 | return 1024 * 4; |
| 21 | } |
| 22 | |
| 23 | /*********************************************************************** |
| 24 | |
| 25 | Return the name of this device |
| 26 | |
| 27 | ***********************************************************************/ |
| 28 | |
| 29 | protected char[] toUtf8() |
| 30 | { |
| 31 | return "<memory>"; |
| 32 | } |
| 33 | |
| 34 | /*********************************************************************** |
| 35 | |
| 36 | Return the underlying OS handle of this Conduit |
| 37 | |
| 38 | ***********************************************************************/ |
| 39 | |
| 40 | final Handle fileHandle () |
| 41 | { |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | /*********************************************************************** |
| 46 | |
| 47 | Return the content held |
| 48 | |
| 49 | ***********************************************************************/ |
| 50 | |
| 51 | final void[] slice () |
| 52 | { |
| 53 | return content; |
| 54 | } |
| 55 | |
| 56 | /*********************************************************************** |
| 57 | |
| 58 | Read a chunk of bytes from the file into the provided |
| 59 | array (typically that belonging to an IBuffer) |
| 60 | |
| 61 | ***********************************************************************/ |
| 62 | |
| 63 | protected override uint read(void[] dst) |
| 64 | { |
| 65 | uint len = Eof; |
| 66 | |
| 67 | if (content.length) |
| 68 | { |
| 69 | len = content.length; |
| 70 | if (len > dst.length) |
| 71 | len = dst.length; |
| 72 | |
| 73 | dst[0 .. len] = content[this._pos .. (len + this._pos)]; |
| 74 | this._pos += len; |
| 75 | } |
| 76 | |
| 77 | return len; |
| 78 | } |
| 79 | |
| 80 | /*********************************************************************** |
| 81 | |
| 82 | Write a chunk of bytes to the file from the provided |
| 83 | array (typically that belonging to an IBuffer) |
| 84 | |
| 85 | ***********************************************************************/ |
| 86 | |
| 87 | protected override uint write (void[] src) |
| 88 | { |
| 89 | content ~= src; |
| 90 | return src.length; |
| 91 | } |
| 92 | |
| 93 | /*********************************************************************** |
| 94 | |
| 95 | Return the position of the conduit |
| 96 | |
| 97 | ***********************************************************************/ |
| 98 | |
| 99 | long position() |
| 100 | { |
| 101 | return this._pos; |
| 102 | } |
| 103 | |
| 104 | /*********************************************************************** |
| 105 | |
| 106 | Basic seek support |
| 107 | |
| 108 | ***********************************************************************/ |
| 109 | |
| 110 | // this doesn't support seeking past the end to grow the array... suppose it could? |
| 111 | long seek(long offset, Seek.Anchor anchor = Seek.Anchor.Begin) |
| 112 | { |
| 113 | long rtn = -1; |
| 114 | |
| 115 | switch (anchor) |
| 116 | { |
| 117 | case Seek.Anchor.Begin: |
| 118 | { |
| 119 | if (offset <= content.length) |
| 120 | this._pos = offset; |
| 121 | break; |
| 122 | } |
| 123 | case Seek.Anchor.Current: |
| 124 | { |
| 125 | if ((offset + this._pos) <= content.length) |
| 126 | this._pos += offset; |
| 127 | break; |
| 128 | } |
| 129 | default: break; |
| 130 | } |
| 131 | |
| 132 | return rtn; |
| 133 | } |
| 134 | |
| 135 | } |
