X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=trace_snappyfile.cpp;h=07a62f6bcc187edb38875a43122abfee2c3ddc7d;hb=f562f318ddee6da2041696887e2195fc3c96d740;hp=5804c3bbb2dc76f9e731554329745ee56b7b53de;hpb=51fade4dcdd16dd03e5fc28e5a63cb5f8a95aa28;p=apitrace

diff --git a/trace_snappyfile.cpp b/trace_snappyfile.cpp
index 5804c3b..07a62f6 100644
--- a/trace_snappyfile.cpp
+++ b/trace_snappyfile.cpp
@@ -28,6 +28,8 @@
 
 #include <snappy.h>
 
+#include <iostream>
+
 #include <assert.h>
 #include <string.h>
 
@@ -201,6 +203,7 @@ void SnappyFile::flushCache()
         if (m_stream.eof())
             return;
         //assert(m_cachePtr == m_cache + m_cacheSize);
+        m_currentOffset.chunk = m_stream.tellg();
         size_t compressedLength;
         compressedLength = readCompressedLength();
         m_stream.read((char*)m_compressedCache, compressedLength);
@@ -240,3 +243,28 @@ uint32_t SnappyFile::readCompressedLength()
     m_stream.read((char*)&len, sizeof len);
     return len;
 }
+
+bool SnappyFile::supportsOffsets() const
+{
+    return true;
+}
+
+File::Offset SnappyFile::currentOffset()
+{
+    m_currentOffset.offsetInChunk = m_cachePtr - m_cache;
+    return m_currentOffset;
+}
+
+void SnappyFile::setCurrentOffset(const File::Offset &offset)
+{
+    // to remove eof bit
+    m_stream.clear();
+    // seek to the start of a chunk
+    m_stream.seekg(offset.chunk, std::ios::beg);
+    // load the chunk
+    flushCache();
+    assert(m_cacheSize >= offset.offsetInChunk);
+    // seek within our cache to the correct location within the chunk
+    m_cachePtr = m_cache + offset.offsetInChunk;
+
+}