diff options
| -rw-r--r-- | c++/src/H5Attribute.cpp | 69 |
1 files changed, 49 insertions, 20 deletions
diff --git a/c++/src/H5Attribute.cpp b/c++/src/H5Attribute.cpp index 80813ba..10601fc 100644 --- a/c++/src/H5Attribute.cpp +++ b/c++/src/H5Attribute.cpp @@ -76,6 +76,7 @@ Attribute::Attribute(const hid_t existing_id) : AbstractDs(existing_id) {} //-------------------------------------------------------------------------- void Attribute::write( const DataType& mem_type, const void *buf ) const { + // Call C function H5Awrite to write data in 'buf' to the attribute herr_t ret_value = H5Awrite( id, mem_type.getId(), buf ); if( ret_value < 0 ) { @@ -98,6 +99,7 @@ void Attribute::write( const DataType& mem_type, const H5std_string& strg ) cons const char* strg_C; strg_C = strg.c_str(); // strg_C refers to the contents of strg as a C-str + // Call C function H5Awrite to write the character string to the attribute herr_t ret_value = H5Awrite( id, mem_type.getId(), &strg_C ); if( ret_value < 0 ) { @@ -115,10 +117,11 @@ void Attribute::write( const DataType& mem_type, const H5std_string& strg ) cons //-------------------------------------------------------------------------- void Attribute::read( const DataType& mem_type, void *buf ) const { + // Call C function H5Aread to read attribute data into 'buf' herr_t ret_value = H5Aread( id, mem_type.getId(), buf ); if( ret_value < 0 ) { - throw AttributeIException("Attribute::read", "H5Aread failed"); + throw AttributeIException("Attribute::read", "H5Aread failed"); } } @@ -130,20 +133,37 @@ void Attribute::read( const DataType& mem_type, void *buf ) const ///\param strg - IN: Buffer for read string ///\exception H5::AttributeIException // Programmer Binh-Minh Ribler - Apr, 2003 +// Modification +// Mar 2008 +// Corrected a misunderstanding that H5Aread would allocate +// space for the buffer. Obtained the attribute size and +// allocated memory properly. - BMR //-------------------------------------------------------------------------- void Attribute::read( const DataType& mem_type, H5std_string& strg ) const { - char* strg_C; // temporary C-string for C API - - // call C API to get the attribute string of chars - herr_t ret_value = H5Aread( id, mem_type.getId(), &strg_C); + // Get the attribute size and allocate temporary C-string for C API + hsize_t attr_size = H5Aget_storage_size(id); + if (attr_size <= 0) + { + throw AttributeIException("Attribute::read", "Unable to get attribute size before reading"); + } + char* strg_C = new char [attr_size+1]; + if (strg_C == NULL) + { + throw AttributeIException("Attribute::read", "Unable to allocate buffer to read the attribute"); + } + // Call C API to get the attribute data, a string of chars + herr_t ret_value = H5Aread(id, mem_type.getId(), &strg_C); if( ret_value < 0 ) { throw AttributeIException("Attribute::read", "H5Aread failed"); } - strg = strg_C; // get 'string' from the C char* - HDfree(strg_C); + + // Get 'string' from the C char* and release resource + strg_C[attr_size] = '\0'; + strg = strg_C; + delete []strg_C; } //-------------------------------------------------------------------------- @@ -232,7 +252,6 @@ H5std_string Attribute::getName( size_t buf_size ) const H5std_string attr_name; ssize_t name_size = getName( buf_size, attr_name ); return( attr_name ); - // let caller catch exception if any } //-------------------------------------------------------------------------- @@ -246,22 +265,32 @@ H5std_string Attribute::getName( size_t buf_size ) const //-------------------------------------------------------------------------- H5std_string Attribute::getName() const { - // Try with 256 characters for the name first, if the name's length - // returned is more than that then, read the name again with the - // appropriate space allocation - char* name_C = new char[256]; // temporary C-string for C API - ssize_t name_size = H5Aget_name(id, 255, name_C); - H5std_string attr_name; - if (name_size >= 256) - name_size = getName(name_size, attr_name); + // Try with 0 and NULL to get the name size + ssize_t name_size = H5Aget_name(id, 0, NULL); - // otherwise, convert the C attribute name and return - else - attr_name = name_C; + // If H5Aget_name returns a negative value, raise an exception, + if (name_size < 0) + { + throw AttributeIException("Attribute::getName", "H5Aget_name failed with 0 and NULL"); + } + + // Allocate temporary C-string for C API + char* name_C = new char[name_size+1]; // temporary C-string for C API + // Calls C routine H5Aget_name again to get the name of the attribute + name_size = H5Aget_name(id, name_size+1, name_C); + + // If H5Aget_name returns a negative value, raise an exception, + if (name_size < 0) + { + throw AttributeIException("Attribute::getName", "H5Aget_name failed"); + } + + // otherwise, convert the C attribute name and return + H5std_string attr_name = name_C; delete []name_C; - return( attr_name ); + return(attr_name); } //-------------------------------------------------------------------------- |