ReadOnlyBufferedStream.cs 4.7 KB

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  1. using System;
  2. using System.IO;
  3. namespace BestHTTP.Extensions
  4. {
  5. public class ReadOnlyBufferedStream : Stream
  6. {
  7. public bool CheckForDataAvailability { get; set; }
  8. Stream stream;
  9. public const int READBUFFER = 8192;
  10. byte[] buf;
  11. int available = 0;
  12. int pos = 0;
  13. public ReadOnlyBufferedStream(Stream nstream)
  14. {
  15. stream = nstream;
  16. buf = VariableSizedBufferPool.Get(READBUFFER, true);
  17. }
  18. public override int Read(byte[] buffer, int offset, int size)
  19. {
  20. if (size <= available)
  21. {
  22. Array.Copy(buf, pos, buffer, offset, size);
  23. available -= size;
  24. pos += size;
  25. return size;
  26. }
  27. else
  28. {
  29. int readcount = 0;
  30. if (available > 0)
  31. {
  32. Array.Copy(buf, pos, buffer, offset, available);
  33. offset += available;
  34. readcount += available;
  35. available = 0;
  36. pos = 0;
  37. }
  38. while (true)
  39. {
  40. try
  41. {
  42. available = stream.Read(buf, 0, buf.Length);
  43. pos = 0;
  44. }
  45. catch (Exception ex)
  46. {
  47. if (readcount > 0)
  48. {
  49. return readcount;
  50. }
  51. throw (ex);
  52. }
  53. if (available < 1)
  54. {
  55. if (readcount > 0)
  56. {
  57. return readcount;
  58. }
  59. return 0;
  60. }
  61. else
  62. {
  63. int toread = size - readcount;
  64. if (toread <= available)
  65. {
  66. Array.Copy(buf, pos, buffer, offset, toread);
  67. available -= toread;
  68. pos += toread;
  69. readcount += toread;
  70. return readcount;
  71. }
  72. else
  73. {
  74. Array.Copy(buf, pos, buffer, offset, available);
  75. offset += available;
  76. readcount += available;
  77. pos = 0;
  78. available = 0;
  79. }
  80. }
  81. }
  82. }
  83. }
  84. public override int ReadByte()
  85. {
  86. if (available > 0)
  87. {
  88. available -= 1;
  89. pos += 1;
  90. return buf[pos - 1];
  91. }
  92. else
  93. {
  94. try
  95. {
  96. available = stream.Read(buf, 0, buf.Length);
  97. pos = 0;
  98. }
  99. catch
  100. {
  101. return -1;
  102. }
  103. if (available < 1)
  104. {
  105. return -1;
  106. }
  107. else
  108. {
  109. available -= 1;
  110. pos += 1;
  111. return buf[pos - 1];
  112. }
  113. }
  114. }
  115. protected override void Dispose(bool disposing)
  116. {
  117. if (buf != null)
  118. VariableSizedBufferPool.Release(buf);
  119. buf = null;
  120. }
  121. public override bool CanRead
  122. {
  123. get { return true; }
  124. }
  125. public override bool CanSeek
  126. {
  127. get { throw new NotImplementedException(); }
  128. }
  129. public override bool CanWrite
  130. {
  131. get { throw new NotImplementedException(); }
  132. }
  133. public override long Length
  134. {
  135. get { throw new NotImplementedException(); }
  136. }
  137. public override long Position
  138. {
  139. get { throw new NotImplementedException(); }
  140. set { throw new NotImplementedException(); }
  141. }
  142. public override void Flush()
  143. {
  144. throw new NotImplementedException();
  145. }
  146. public override long Seek(long offset, SeekOrigin origin)
  147. {
  148. throw new NotImplementedException();
  149. }
  150. public override void SetLength(long value)
  151. {
  152. throw new NotImplementedException();
  153. }
  154. public override void Write(byte[] buffer, int offset, int count)
  155. {
  156. throw new NotImplementedException();
  157. }
  158. }
  159. }