/symbols/pdb/Microsoft.Cci.Pdb/PdbFileHeader.cs

 1// Copyright (c) Microsoft. All rights reserved.
 2// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 3
 4using System;
 5using System.IO;
 6using System.Linq;
 7using System.Text;
 8
 9namespace Microsoft.Cci.Pdb {
10  internal class PdbFileHeader {
11    private readonly byte[] windowsPdbMagic = new byte[32] {
12                  0x4D, 0x69, 0x63, 0x72, 0x6F, 0x73, 0x6F, 0x66, // "Microsof"
13                  0x74, 0x20, 0x43, 0x2F, 0x43, 0x2B, 0x2B, 0x20, // "t C/C++ "
14                  0x4D, 0x53, 0x46, 0x20, 0x37, 0x2E, 0x30, 0x30, // "MSF 7.00"
15                  0x0D, 0x0A, 0x1A, 0x44, 0x53, 0x00, 0x00, 0x00  // "^^^DS^^^"
16    };
17
18    //internal PdbFileHeader(int pageSize) {
19    //  this.magic = new byte[32] {
20    //            0x4D, 0x69, 0x63, 0x72, 0x6F, 0x73, 0x6F, 0x66, // "Microsof"
21    //            0x74, 0x20, 0x43, 0x2F, 0x43, 0x2B, 0x2B, 0x20, // "t C/C++ "
22    //            0x4D, 0x53, 0x46, 0x20, 0x37, 0x2E, 0x30, 0x30, // "MSF 7.00"
23    //            0x0D, 0x0A, 0x1A, 0x44, 0x53, 0x00, 0x00, 0x00  // "^^^DS^^^"
24    //        };
25    //  this.pageSize = pageSize;
26    //}
27
28    internal PdbFileHeader(Stream reader, BitAccess bits) {
29      bits.MinCapacity(56);
30      reader.Seek(0, SeekOrigin.Begin);
31      bits.FillBuffer(reader, 52);
32
33      this.magic = new byte[32];
34      bits.ReadBytes(this.magic);                 //   0..31
35      bits.ReadInt32(out this.pageSize);          //  32..35
36      bits.ReadInt32(out this.freePageMap);       //  36..39
37      bits.ReadInt32(out this.pagesUsed);         //  40..43
38      bits.ReadInt32(out this.directorySize);     //  44..47
39      bits.ReadInt32(out this.zero);              //  48..51
40
41      if (!this.magic.SequenceEqual(windowsPdbMagic))
42      {
43        throw new PdbException("The PDB file is not recognized as a Windows PDB file");
44      }
45
46      int directoryPages = ((((directorySize + pageSize - 1) / pageSize) * 4) + pageSize - 1) / pageSize;
47      this.directoryRoot = new int[directoryPages];
48      bits.FillBuffer(reader, directoryPages * 4);
49      bits.ReadInt32(this.directoryRoot);
50    }
51
52    //internal string Magic {
53    //  get { return StringFromBytesUTF8(magic); }
54    //}
55
56    //internal void Write(Stream writer, BitAccess bits) {
57    //  bits.MinCapacity(pageSize);
58    //  bits.WriteBytes(magic);                     //   0..31
59    //  bits.WriteInt32(pageSize);                  //  32..35
60    //  bits.WriteInt32(freePageMap);               //  36..39
61    //  bits.WriteInt32(pagesUsed);                 //  40..43
62    //  bits.WriteInt32(directorySize);             //  44..47
63    //  bits.WriteInt32(zero);                      //  48..51
64    //  bits.WriteInt32(directoryRoot);             //  52..55
65
66    //  writer.Seek(0, SeekOrigin.Begin);
67    //  bits.WriteBuffer(writer, pageSize);
68    //}
69
70    //////////////////////////////////////////////////// Helper Functions.
71    //
72    //internal static string StringFromBytesUTF8(byte[] bytes) {
73    //  return StringFromBytesUTF8(bytes, 0, bytes.Length);
74    //}
75
76    //internal static string StringFromBytesUTF8(byte[] bytes, int offset, int length) {
77    //  for (int i = 0; i < length; i++) {
78    //    if (bytes[offset + i] < ' ') {
79    //      length = i;
80    //    }
81    //  }
82    //  return Encoding.UTF8.GetString(bytes, offset, length);
83    //}
84
85    ////////////////////////////////////////////////////////////// Fields.
86    //
87    internal readonly byte[] magic;
88    internal readonly int pageSize;
89    internal int freePageMap;
90    internal int pagesUsed;
91    internal int directorySize;
92    internal readonly int zero;
93    internal int[] directoryRoot;
94  }
95
96}