backport fix #276 (#282)

mdal/frmts/mdal_selafin.cpp

@@ -25,7 +25,7 @@
 
 MDAL::SerafinStreamReader::SerafinStreamReader() = default;
 
-void MDAL::SerafinStreamReader::initialize( const std::string &fileName )
+bool MDAL::SerafinStreamReader::initialize( const std::string &fileName )
 {
   mFileName = fileName;
   if ( !MDAL::fileExists( mFileName ) )
@@ -42,8 +42,23 @@ void MDAL::SerafinStreamReader::initialize( const std::string &fileName )
   mFileSize = mIn.tellg();
   mIn.seekg( 0, mIn.beg );
 
-  mStreamInFloatPrecision = getStreamPrecision();
-  mIsNativeLittleEndian = MDAL::isNativeLittleEndian();
+  mChangeEndianness = MDAL::isNativeLittleEndian();
+
+  //Check if need to change the endianness
+  // read first size_t that has to be 80
+  size_t firstInt = read_sizet();
+  mIn.seekg( 0, mIn.beg );
+  if ( firstInt != 80 )
+  {
+    mChangeEndianness = !mChangeEndianness;
+    //Retry
+    firstInt = read_sizet();
+    if ( firstInt != 80 )
+      throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "File " + mFileName + " could not be open" );
+    mIn.seekg( 0, mIn.beg );
+  }
+
+  return readHeader();
 }
 
 bool MDAL::SerafinStreamReader::getStreamPrecision( )
@@ -68,6 +83,27 @@ bool MDAL::SerafinStreamReader::getStreamPrecision( )
   return ret;
 }
 
+bool MDAL::SerafinStreamReader::readHeader()
+{
+  std::string header = read_string( 80 );
+  std::string varType = header.substr( 72, 8 );
+  varType = trim( varType );
+
+  if ( varType == "SERAFIN" )
+    mStreamInFloatPrecision = true;
+  else if ( varType == "SERAFIND" )
+    mStreamInFloatPrecision = false;
+  else
+    throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Not found stream precision" );
+
+  return true;
+}
+
+bool MDAL::SerafinStreamReader::streamInFloatPrecision() const
+{
+  return mStreamInFloatPrecision;
+}
+
 std::string MDAL::SerafinStreamReader::read_string( size_t len )
 {
   size_t length = read_sizet();
@@ -150,13 +186,13 @@ double MDAL::SerafinStreamReader::read_double( )
   if ( mStreamInFloatPrecision )
   {
     float ret_f;
-    if ( !readValue( ret_f, mIn, mIsNativeLittleEndian ) )
+    if ( !readValue( ret_f, mIn, mChangeEndianness ) )
       throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Reading double failed" );
     ret = static_cast<double>( ret_f );
   }
   else
   {
-    if ( !readValue( ret, mIn, mIsNativeLittleEndian ) )
+    if ( !readValue( ret, mIn, mChangeEndianness ) )
       throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Reading double failed" );
   }
   return ret;
@@ -170,7 +206,7 @@ int MDAL::SerafinStreamReader::read_int( )
   if ( mIn.read( reinterpret_cast< char * >( &data ), 4 ) )
     if ( !mIn )
       throw MDAL::Error( MDAL_Status::Err_UnknownFormat, "Unable to open stream for reading int" );
-  if ( mIsNativeLittleEndian )
+  if ( mChangeEndianness )
   {
     std::reverse( reinterpret_cast< char * >( &data ), reinterpret_cast< char * >( &data ) + 4 );
   }
@@ -341,8 +377,8 @@ void MDAL::DriverSelafin::parseFile( std::vector<std::string> &var_names,
      - NBV(1)+NBV(2) records containing the results tables for each variable at time
   */
   data.resize( var_names.size() );
-
-  size_t nTimesteps = mReader.remainingBytes() / ( 12 + ( 4 + ( *nPoint ) * 4 + 4 ) * var_names.size() );
+  size_t realSize = mReader.streamInFloatPrecision() ? 4 : 8;
+  size_t nTimesteps = mReader.remainingBytes() / ( 8 + realSize + ( 4 + ( *nPoint ) * realSize + 4 ) *  var_names.size() );
   for ( size_t nT = 0; nT < nTimesteps; ++nT )
   {
     std::vector<double> times = mReader.read_double_arr( 1 );
@@ -536,28 +572,16 @@ bool MDAL::DriverSelafin::canReadMesh( const std::string &uri )
 {
   if ( !MDAL::fileExists( uri ) ) return false;
 
-  std::ifstream in( uri, std::ifstream::in | std::ifstream::binary );
-  if ( !in ) return false;
-
-  // The first four bytes of the file should contain the values (in hexadecimal): 00 00 00 50.
-  // This actually indicates the start of a string of length 80 in the file.
-  // At position 84 in the file, the eight next bytes should read (in hexadecimal): 00 00 00 50 00 00 00 04.
-  unsigned char data[ 92 ];
-  in.read( reinterpret_cast< char * >( &data ), 92 );
-  if ( !in )
-    return false;
-
-  if ( data[0] != 0 || data[1] != 0 ||
-       data[2] != 0 || data[3] != 0x50 )
-    return false;
-
-  if ( data[84 + 0] != 0 || data[84 + 1] != 0 ||
-       data[84 + 2] != 0 || data[84 + 3] != 0x50 ||
-       data[84 + 4] != 0 || data[84 + 5] != 0 ||
-       data[84 + 6] != 0 || data[84 + 7] != 8 )
+  try
+  {
+    SerafinStreamReader reader;
+    return reader.initialize( uri );
+  }
+  catch ( MDAL::Error )
+  {
     return false;
+  }
 
-  return true;
 }
 
 std::unique_ptr<MDAL::Mesh> MDAL::DriverSelafin::load( const std::string &meshFile, const std::string & )

mdal/frmts/mdal_selafin.hpp

@@ -16,14 +16,15 @@
 #include "mdal_memory_data_model.hpp"
 #include "mdal.h"
 #include "mdal_driver.hpp"
+#include "mdal_utils.hpp"
 
 namespace MDAL
 {
   class SerafinStreamReader
   {
     public:
       SerafinStreamReader();
-      void initialize( const std::string &fileName );
+      bool initialize( const std::string &fileName );
 
       std::string read_string( size_t len );
       std::vector<double> read_double_arr( size_t len );
@@ -35,6 +36,10 @@ namespace MDAL
       size_t read_sizet( );
 
       size_t remainingBytes();
+
+      //! Return true if is float precision
+      bool streamInFloatPrecision() const;
+
     private:
       void ignore_array_length( );
       std::string read_string_without_length( size_t len );
@@ -43,9 +48,11 @@ namespace MDAL
 
       std::string mFileName;
       bool mStreamInFloatPrecision = true;
-      bool mIsNativeLittleEndian = true;
+      bool mChangeEndianness = true;
       long long mFileSize = -1;
       std::ifstream mIn;
+
+      bool readHeader();
   };
 
   /**

tests/data/slf/README.TXT

@@ -0,0 +1,33 @@
+test_sd_6
+---------
+
+format: double precision floating point
+CRS: EPSG 25832
+
+created with: Janet (v2.24.00)
+number of timesteps: 1
+parameters: X, Y, B, W
+
+
+test_sd_7
+---------
+
+format: double precision floating point
+CRS: EPSG 25832
+
+created with: Telemac2D (v7p2r0)
+number of timesteps: 11
+parameters: X, Y, U, V, H, S, B, Q, M, W, L, US
+
+where
+ - U="velocity along x axis  (m/s)"
+ - V="velocity along y axis  (m/s)"
+ - H="water depth  (m)"
+ - S="free surface elevation  (m)"
+ - B="bottom elevation  (m)"
+ - F="Froude number  "
+ - M="scalar velocity  (m/s)"
+ - W="friction coefficient"
+ - L="Courant number "
+ - US="friction velocity  "
+