1 //-----------------------------------------------------------------------------
3 // Copyright (C) Microsoft Corporation. All Rights Reserved.
5 //-----------------------------------------------------------------------------
9 namespace Microsoft.Cci.Pdb {
10 internal class DataStream {
11 internal DataStream() {
16 internal DataStream(int contentSize, BitAccess bits, int count) {
17 this.contentSize = contentSize;
19 this.pages = new int[count];
20 bits.ReadInt32(this.pages);
24 internal void Read(PdbReader reader, BitAccess bits) {
25 bits.MinCapacity(contentSize);
26 Read(reader, 0, bits.Buffer, 0, contentSize);
29 internal void Read(PdbReader reader, int position,
30 byte[] bytes, int offset, int data) {
31 if (position + data > contentSize) {
32 throw new PdbException("DataStream can't read off end of stream. " +
36 if (position == contentSize) {
41 int page = position / reader.pageSize;
42 int rema = position % reader.pageSize;
44 // First get remained of first page.
46 int todo = reader.pageSize - rema;
51 reader.Seek(pages[page], rema);
52 reader.Read(bytes, offset, todo);
59 // Now get the remaining pages.
61 int todo = reader.pageSize;
66 reader.Seek(pages[page], 0);
67 reader.Read(bytes, offset, todo);
75 internal void Write(PdbWriter writer, byte[] bytes) {
76 Write(writer, bytes, bytes.Length);
79 internal void Write(PdbWriter writer, byte[] bytes, int data) {
80 if (bytes == null || data == 0) {
86 int rema = contentSize % writer.pageSize;
88 int todo = writer.pageSize - rema;
93 int lastPage = pages[pages.Length - 1];
94 writer.Seek(lastPage, rema);
95 writer.Write(bytes, used, todo);
101 int count = (left + writer.pageSize - 1) / writer.pageSize;
102 int page0 = writer.AllocatePages(count);
104 writer.Seek(page0, 0);
105 writer.Write(bytes, used, left);
107 AddPages(page0, count);
113 private void AddPages(int page0, int count) {
115 pages = new int[count];
116 for (int i = 0; i < count; i++) {
117 pages[i] = page0 + i;
121 int used = old.Length;
123 pages = new int[used + count];
124 Array.Copy(old, pages, used);
125 for (int i = 0; i < count; i++) {
126 pages[used + i] = page0 + i;
132 get { return pages == null ? 0 : pages.Length; }
135 internal int Length {
136 get { return contentSize; }
139 internal int GetPage(int index) {
143 internal int contentSize;
144 internal int[] pages;