#include "wx/textfile.h"
#include "wx/filename.h"
+#include "wx/buffer.h"
// ============================================================================
// wxTextFile class implementation
}
-bool wxTextFile::OnRead(wxMBConv& conv)
+bool wxTextFile::OnRead(const wxMBConv& conv)
{
- // file should be opened and we must be in it's beginning
- wxASSERT( m_file.IsOpened() &&
- (m_file.GetKind() != wxFILE_KIND_DISK || m_file.Tell() == 0) );
-
- char buf[1025];
- wxChar chLast = '\0';
- wxString str;
+ // file should be opened
+ wxASSERT_MSG( m_file.IsOpened(), _T("can't read closed file") );
+
+ // read the entire file in memory: this is not the most efficient thing to
+ // do it but there is no good way to avoid it in Unicode build because if
+ // we read the file block by block we can't convert each block to Unicode
+ // separately (the last multibyte char in the block might be only partially
+ // read and so the conversion would fail) and, as the file contents is kept
+ // in memory by wxTextFile anyhow, it shouldn't be a big problem to read
+ // the file entirely
+ size_t bufSize = 0;
+
+ // number of bytes to (try to) read from disk at once
+ static const size_t BLOCK_SIZE = 4096;
+
+ wxCharBuffer buf;
+
+ // first determine if the file is seekable or not and so whether we can
+ // determine its length in advance
+ wxFileOffset fileLength;
+ {
+ wxLogNull logNull;
+ fileLength = m_file.Length();
+ }
- for ( ;; )
+ // some non-seekable files under /proc under Linux pretend that they're
+ // seekable but always return 0; others do return an error
+ const bool seekable = fileLength != wxInvalidOffset && fileLength != 0;
+ if ( seekable )
{
- // leave space for trailing NUL
- ssize_t nRead = m_file.Read(buf, WXSIZEOF(buf) - 1);
+ // we know the required length, so set the buffer size in advance
+ bufSize = fileLength;
+ if ( !buf.extend(bufSize) )
+ return false;
+
+ // if the file is seekable, also check that we're at its beginning
+ wxASSERT_MSG( m_file.Tell() == 0, _T("should be at start of file") );
- if ( nRead == wxInvalidOffset )
+ char *dst = buf.data();
+ for ( size_t nRemaining = bufSize; nRemaining > 0; )
{
- // read error (error message already given in wxFile::Read)
- return false;
- }
+ size_t nToRead = BLOCK_SIZE;
- if ( nRead == 0 )
- break;
+ // the file size could have changed, avoid overflowing the buffer
+ // even if it did
+ if ( nToRead > nRemaining )
+ nToRead = nRemaining;
+
+ ssize_t nRead = m_file.Read(dst, nToRead);
+
+ if ( nRead == wxInvalidOffset )
+ {
+ // read error (error message already given in wxFile::Read)
+ return false;
+ }
- buf[nRead] = '\0';
+ if ( nRead == 0 )
+ {
+ // this file can't be empty because we checked for this above
+ // so this must be the end of file
+ break;
+ }
- // append to the remains of the last block, don't overwrite
- str += wxString(buf, conv);
+ dst += nRead;
+ nRemaining -= nRead;
+ }
- // the beginning of the current line, changes inside the loop
- const wxChar *lineStart = str.begin();
- const wxChar * const end = str.end();
- for ( const wxChar *p = lineStart; p != end; p++ )
+ wxASSERT_MSG( dst - buf.data() == (wxFileOffset)bufSize,
+ _T("logic error") );
+ }
+ else // file is not seekable
+ {
+ char block[BLOCK_SIZE];
+ for ( ;; )
{
- const wxChar ch = *p;
- switch ( ch )
+ ssize_t nRead = m_file.Read(block, WXSIZEOF(block));
+
+ if ( nRead == wxInvalidOffset )
{
- case '\n':
- // could be a DOS or Unix EOL
- if ( chLast == '\r' )
+ // read error (error message already given in wxFile::Read)
+ return false;
+ }
+
+ if ( nRead == 0 )
+ {
+ // if no bytes have been read, presumably this is a
+ // valid-but-empty file
+ if ( bufSize == 0 )
+ return true;
+
+ // otherwise we've finished reading the file
+ break;
+ }
+
+ // extend the buffer for new data
+ if ( !buf.extend(bufSize + nRead) )
+ return false;
+
+ // and append it to the buffer
+ memcpy(buf.data() + bufSize, block, nRead);
+ bufSize += nRead;
+ }
+ }
+
+ const wxString str(buf, conv, bufSize);
+
+ // there's no risk of this happening in ANSI build
+#if wxUSE_UNICODE
+ if ( bufSize > 4 && str.empty() )
+ {
+ wxLogError(_("Failed to convert file \"%s\" to Unicode."), GetName());
+ return false;
+ }
+#endif // wxUSE_UNICODE
+
+ // we don't need this memory any more
+ buf.reset();
+
+
+ // now break the buffer in lines
+
+ // last processed character, we need to know if it was a CR or not
+ wxChar chLast = '\0';
+
+ // the beginning of the current line, changes inside the loop
+ wxString::const_iterator lineStart = str.begin();
+ const wxString::const_iterator end = str.end();
+ for ( wxString::const_iterator p = lineStart; p != end; p++ )
+ {
+ const wxChar ch = *p;
+ switch ( ch )
+ {
+ case '\n':
+ // could be a DOS or Unix EOL
+ if ( chLast == '\r' )
+ {
+ if ( p - 1 >= lineStart )
{
AddLine(wxString(lineStart, p - 1), wxTextFileType_Dos);
}
- else // bare '\n', Unix style
+ else
{
- AddLine(wxString(lineStart, p), wxTextFileType_Unix);
+ // there were two line endings, so add an empty line:
+ AddLine(wxEmptyString, wxTextFileType_Dos);
}
-
+ }
+ else // bare '\n', Unix style
+ {
+ AddLine(wxString(lineStart, p), wxTextFileType_Unix);
+ }
+
+ lineStart = p + 1;
+ break;
+
+ case '\r':
+ if ( chLast == '\r' )
+ {
+ // Mac empty line
+ AddLine(wxEmptyString, wxTextFileType_Mac);
lineStart = p + 1;
- break;
-
- case '\r':
- if ( chLast == '\r' )
+ }
+ //else: we don't know what this is yet -- could be a Mac EOL or
+ // start of DOS EOL so wait for next char
+ break;
+
+ default:
+ if ( chLast == '\r' )
+ {
+ // Mac line termination
+ if ( p - 1 >= lineStart )
{
- // Mac empty line
- AddLine(wxEmptyString, wxTextFileType_Mac);
- lineStart = p + 1;
+ AddLine(wxString(lineStart, p - 1), wxTextFileType_Mac);
}
- //else: we don't what this is yet -- could be a Mac EOL or
- // start of DOS EOL so wait for next char
- break;
-
- default:
- if ( chLast == '\r' )
+ else
{
- // Mac line termination
- AddLine(wxString(lineStart, p - 1), wxTextFileType_Mac);
- lineStart = p;
+ // there were two line endings, so add an empty line:
+ AddLine(wxEmptyString, wxTextFileType_Mac);
}
- }
-
- chLast = ch;
+ lineStart = p;
+ }
}
- // remove the part we already processed
- str.erase(0, lineStart - str.begin());
+ chLast = ch;
}
// anything in the last line?
- if ( !str.empty() )
+ if ( lineStart != end )
{
- AddLine(str, wxTextFileType_None); // no line terminator
+ // add unterminated last line
+ AddLine(wxString(lineStart, end), wxTextFileType_None);
}
return true;
}
-bool wxTextFile::OnWrite(wxTextFileType typeNew, wxMBConv& conv)
+bool wxTextFile::OnWrite(wxTextFileType typeNew, const wxMBConv& conv)
{
wxFileName fn = m_strBufferName;
}
#endif // wxUSE_TEXTFILE
-
projects / wxWidgets.git / blobdiff