Imported Upstream version 5.0.0.42

Former-commit-id: fd56571888259555122d8a0f58c68838229cea2b

external/linker/cecil/symbols/pdb/Microsoft.Cci.Pdb/DataStream.cs

@@ -0,0 +1,111 @@
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) Microsoft. All rights reserved.
+// This code is licensed under the Microsoft Public License.
+// THIS CODE IS PROVIDED *AS IS* WITHOUT WARRANTY OF
+// ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY
+// IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR
+// PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.
+//
+//-----------------------------------------------------------------------------
+using System;
+using System.IO;
+
+namespace Microsoft.Cci.Pdb {
+  internal class DataStream {
+    internal DataStream() {
+    }
+
+    internal DataStream(int contentSize, BitAccess bits, int count) {
+      this.contentSize = contentSize;
+      if (count > 0) {
+        this.pages = new int[count];
+        bits.ReadInt32(this.pages);
+      }
+    }
+
+    internal void Read(PdbReader reader, BitAccess bits) {
+      bits.MinCapacity(contentSize);
+      Read(reader, 0, bits.Buffer, 0, contentSize);
+    }
+
+    internal void Read(PdbReader reader, int position,
+                     byte[] bytes, int offset, int data) {
+      if (position + data > contentSize) {
+        throw new PdbException("DataStream can't read off end of stream. " +
+                                       "(pos={0},siz={1})",
+                               position, data);
+      }
+      if (position == contentSize) {
+        return;
+      }
+
+      int left = data;
+      int page = position / reader.pageSize;
+      int rema = position % reader.pageSize;
+
+      // First get remained of first page.
+      if (rema != 0) {
+        int todo = reader.pageSize - rema;
+        if (todo > left) {
+          todo = left;
+        }
+
+        reader.Seek(pages[page], rema);
+        reader.Read(bytes, offset, todo);
+
+        offset += todo;
+        left -= todo;
+        page++;
+      }
+
+      // Now get the remaining pages.
+      while (left > 0) {
+        int todo = reader.pageSize;
+        if (todo > left) {
+          todo = left;
+        }
+
+        reader.Seek(pages[page], 0);
+        reader.Read(bytes, offset, todo);
+
+        offset += todo;
+        left -= todo;
+        page++;
+      }
+    }
+
+    //private void AddPages(int page0, int count) {
+    //  if (pages == null) {
+    //    pages = new int[count];
+    //    for (int i = 0; i < count; i++) {
+    //      pages[i] = page0 + i;
+    //    }
+    //  } else {
+    //    int[] old = pages;
+    //    int used = old.Length;
+
+    //    pages = new int[used + count];
+    //    Array.Copy(old, pages, used);
+    //    for (int i = 0; i < count; i++) {
+    //      pages[used + i] = page0 + i;
+    //    }
+    //  }
+    //}
+
+    //internal int Pages {
+    //  get { return pages == null ? 0 : pages.Length; }
+    //}
+
+    internal int Length {
+      get { return contentSize; }
+    }
+
+    //internal int GetPage(int index) {
+    //  return pages[index];
+    //}
+
+    internal int contentSize;
+    internal int[] pages;
+  }
+}