import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

toolkit/components/url-classifier/ChunkSet.h

@@ -0,0 +1,99 @@
+//* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ChunkSet_h__
+#define ChunkSet_h__
+
+#include "Entries.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace safebrowsing {
+
+/**
+ * Store the chunk numbers as an array of ranges of uint32_t.
+ * We need chunk numbers in order to ask for incremental updates from the
+ * server.
+ */
+class ChunkSet {
+public:
+  nsresult Serialize(nsACString& aStr);
+  nsresult Set(uint32_t aChunk);
+  bool Has(uint32_t chunk) const;
+  nsresult Merge(const ChunkSet& aOther);
+  uint32_t Length() const;
+  nsresult Remove(const ChunkSet& aOther);
+  void Clear();
+
+  nsresult Write(nsIOutputStream* aOut);
+  nsresult Read(nsIInputStream* aIn, uint32_t aNumElements);
+
+private:
+  class Range {
+  public:
+    Range(uint32_t aBegin, uint32_t aEnd) : mBegin(aBegin), mEnd(aEnd) {}
+
+    uint32_t Length() const;
+    nsresult Remove(const Range& aRange, ChunkSet& aRemainderSet) const;
+    bool FoldLeft(const Range& aRange);
+
+    bool operator==(const Range& rhs) const {
+      return mBegin == rhs.mBegin;
+    }
+    bool operator<(const Range& rhs) const {
+      return mBegin < rhs.mBegin;
+    }
+
+    uint32_t Begin() const {
+      return mBegin;
+    }
+    void Begin(const uint32_t aBegin) {
+      mBegin = aBegin;
+    }
+    uint32_t End() const {
+      return mEnd;
+    }
+    void End(const uint32_t aEnd) {
+      mEnd = aEnd;
+    }
+
+    bool Contains(const Range& aRange) const {
+      return mBegin <= aRange.mBegin && aRange.mEnd <= mEnd;
+    }
+    bool Precedes(const Range& aRange) const {
+      return mEnd + 1 == aRange.mBegin;
+    }
+
+    struct IntersectionComparator {
+      int operator()(const Range& aRange) const {
+        if (aRange.mBegin > mTarget.mEnd) {
+          return -1;
+        }
+        if (mTarget.mBegin > aRange.mEnd) {
+          return 1;
+        }
+        return 0;
+      }
+
+      explicit IntersectionComparator(const Range& aTarget) : mTarget(aTarget){}
+      const Range& mTarget;
+    };
+
+  private:
+    uint32_t mBegin;
+    uint32_t mEnd;
+  };
+
+  static const size_t IO_BUFFER_SIZE = 1024;
+  FallibleTArray<Range> mRanges;
+
+  bool HasSubrange(const Range& aSubrange) const;
+};
+
+} // namespace safebrowsing
+} // namespace mozilla
+
+#endif