X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=trace_snappyfile.cpp;h=c350013d7f1acc7e7ff1546fa860019f94d47762;hb=2257168033b52be3094efdbd7eadff8eb77a4c4e;hp=7e7072543426851c125257d2c9d0b5e0367e3e86;hpb=d4ca4e2090572b9bf8430c9d4ece5cb9c9b6528e;p=apitrace

diff --git a/trace_snappyfile.cpp b/trace_snappyfile.cpp
index 7e70725..c350013 100644
--- a/trace_snappyfile.cpp
+++ b/trace_snappyfile.cpp
@@ -28,6 +28,8 @@
 
 #include <snappy.h>
 
+#include <iostream>
+
 #include <assert.h>
 #include <string.h>
 
@@ -205,6 +207,7 @@ void SnappyFile::flushCache()
         assert(m_cachePtr == m_cache);
     } else if (m_mode == File::Read) {
         //assert(m_cachePtr == m_cache + m_cacheSize);
+        m_currentOffset.chunk = m_stream.tellg();
         size_t compressedLength;
         compressedLength = readCompressedLength();
 
@@ -265,3 +268,52 @@ size_t SnappyFile::readCompressedLength()
     }
     return length;
 }
+
+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;
+
+}
+
+bool SnappyFile::rawSkip(unsigned length)
+{
+    if (endOfData()) {
+        return false;
+    }
+
+    if (freeCacheSize() >= length) {
+        m_cachePtr += length;
+    } else {
+        int sizeToRead = length;
+        while (sizeToRead) {
+            int chunkSize = std::min(freeCacheSize(), sizeToRead);
+            m_cachePtr += chunkSize;
+            sizeToRead -= chunkSize;
+            if (sizeToRead > 0)
+                flushCache();
+            if (!m_cacheSize)
+                break;
+        }
+    }
+
+    return true;
+}