Chunk large reads into multiple smaller reads of max 64MB.

3 files changed, 18 insertions, 14 deletions

diff --git a/fastos/src/vespa/fastos/file.cpp b/fastos/src/vespa/fastos/file.cpp
index 1382aef7386..15a817c0bff 100644
--- a/fastos/src/vespa/fastos/file.cpp
+++ b/fastos/src/vespa/fastos/file.cpp
@@ -34,11 +34,11 @@ int FastOS_FileInterface::_defaultFAdviseOptions = POSIX_FADV_NORMAL;
 int FastOS_FileInterface::_defaultFAdviseOptions = 0;
 #endif
 
-static const size_t MAX_WRITE_CHUNK_SIZE = 0x4000000; // 64 MB
+static const size_t MAX_CHUNK_SIZE = 0x4000000; // 64 MB
 
 FastOS_FileInterface::FastOS_FileInterface(const char *filename)
     : _fAdviseOptions(_defaultFAdviseOptions),
-      _writeChunkSize(MAX_WRITE_CHUNK_SIZE),
+      _chunkSize(MAX_CHUNK_SIZE),
       _filename(),
       _openFlags(0),
       _directIOEnabled(false),
@@ -140,13 +140,6 @@ FastOS_FileInterface::EnableDirectIO()
 
 
 void
-FastOS_FileInterface::SetWriteChunkSize(size_t writeChunkSize)
-{
-    _writeChunkSize = writeChunkSize;
-}
-
-
-void
 FastOS_FileInterface::EnableSyncWrites()
 {
     if (!IsOpened())
diff --git a/fastos/src/vespa/fastos/file.h b/fastos/src/vespa/fastos/file.h
index 2d83a1766f0..a352c6281a3 100644
--- a/fastos/src/vespa/fastos/file.h
+++ b/fastos/src/vespa/fastos/file.h
@@ -84,7 +84,7 @@ private:
     // And setFAdviseOptions() per file.
     static int    _defaultFAdviseOptions;
     int           _fAdviseOptions;
-    size_t        _writeChunkSize;
+    size_t        _chunkSize;
     void WriteBufInternal(const void *buffer, size_t length);
 
 protected:
@@ -485,8 +485,8 @@ public:
     /**
      * Set the write chunk size used in WriteBuf.
      */
-    void SetWriteChunkSize(size_t writeChunkSize);
-    size_t getWriteChunkSize() const { return _writeChunkSize; }
+    void setChunkSize(size_t chunkSize) { _chunkSize = chunkSize; }
+    size_t getChunkSize() const { return _chunkSize; }
 
     /**
      * Get restrictions for direct disk I/O. The file should be opened
diff --git a/fastos/src/vespa/fastos/linux_file.cpp b/fastos/src/vespa/fastos/linux_file.cpp
index 3a59b862a52..27beb1242d1 100644
--- a/fastos/src/vespa/fastos/linux_file.cpp
+++ b/fastos/src/vespa/fastos/linux_file.cpp
@@ -44,7 +44,18 @@ FastOS_Linux_File::readInternal(int fh, void *buffer, size_t length, int64_t rea
 ssize_t
 FastOS_Linux_File::readInternal(int fh, void *buffer, size_t length)
 {
-    return File_RW_Ops::read(fh, buffer, length);
+    char * data = static_cast<char *>(buffer);
+    ssize_t read(0);
+    while (read < ssize_t(length)) {
+        size_t lenNow = std::min(getChunkSize(), length - read);
+        ssize_t readNow = File_RW_Ops::read(fh, data + read, lenNow);
+        if (readNow > 0) {
+            read += readNow;
+        } else {
+            return (read > 0) ? read : readNow;
+        }
+    }
+    return read;
 }
 
 
@@ -169,7 +180,7 @@ FastOS_Linux_File::Write2(const void *buffer, size_t length)
     const char * data = static_cast<const char *>(buffer);
     ssize_t written(0);
     while (written < ssize_t(length)) {
-        size_t lenNow = std::min(getWriteChunkSize(), length - written);
+        size_t lenNow = std::min(getChunkSize(), length - written);
         ssize_t writtenNow = internalWrite2(data + written, lenNow);
         if (writtenNow > 0) {
             written += writtenNow;