changeset 1078:ce82bcdc95d0

Fail upfront if the file is going to be too large. We expect the caller to split up large data sets into several MatrixFiles
author Chris Cannam
date Wed, 10 Jun 2015 13:10:26 +0100 (2015-06-10)
parents ec6e7f0f3f5b
children 6ea7761a418b
files data/fileio/MatrixFile.cpp
diffstat 1 files changed, 11 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/data/fileio/MatrixFile.cpp	Wed Jun 10 13:09:14 2015 +0100
+++ b/data/fileio/MatrixFile.cpp	Wed Jun 10 13:10:26 2015 +0100
@@ -89,6 +89,16 @@
         throw FileOperationFailed(fileName, "create");
     }
 
+    // Use floating-point here to avoid integer overflow. We can be
+    // approximate so long as we are on the cautious side
+    if ((double(m_width) * m_height) * m_cellSize + m_headerSize + m_width >=
+        pow(2, 31) - 10.0) { // bit of slack there
+        cerr << "ERROR: MatrixFile::MatrixFile: width " << m_width
+             << " is too large for height " << m_height << " and cell size "
+             << m_cellSize << " (should be using multiple files)" << endl;
+        throw FileOperationFailed(fileName, "size");
+    }
+    
     m_flags = 0;
     m_fmode = S_IRUSR | S_IWUSR;
 
@@ -203,7 +213,7 @@
     off_t off = m_headerSize + (m_width * m_height * m_cellSize) + m_width;
 
 #ifdef DEBUG_MATRIX_FILE
-    cerr << "MatrixFile[" << m_fd << "]::initialise(" << m_width << ", " << m_height << "): cell size " << m_cellSize << ", header size " << m_headerSize << ", resizing file" << endl;
+    cerr << "MatrixFile[" << m_fd << "]::initialise(" << m_width << ", " << m_height << "): cell size " << m_cellSize << ", header size " << m_headerSize << ", resizing fd " << m_fd << " to " << off << endl;
 #endif
 
     if (::lseek(m_fd, off - 1, SEEK_SET) < 0) {