Make GraphicsConverter threadsafe

[lyx.git] / src / support / filetools.cpp

diff --git a/src/support/filetools.cpp b/src/support/filetools.cpp
index b9c7e7f01a66ee642c2b2cb8a8886411f096ba00..d167d6a94cb1a52ddd7b5401c6a2c17a513ee3f8 100644 (file)
--- a/src/support/filetools.cpp
+++ b/src/support/filetools.cpp
@@ -43,6 +43,9 @@
 #include "support/regex.h"
 
 #include <fcntl.h>
+#ifdef HAVE_MAGIC_H
+#include <magic.h>
+#endif
 
 #include <cerrno>
 #include <cstdlib>
@@ -91,6 +94,60 @@ bool isValidDVIFileName(string const & filename)
 }
 
 
+bool isBinaryFile(FileName const & filename)
+{
+       bool isbinary = false;
+       if (filename.empty() || !filename.exists())
+               return isbinary;
+
+#ifdef HAVE_MAGIC_H
+       magic_t magic_cookie = magic_open(MAGIC_MIME_ENCODING);
+       if (magic_cookie) {
+               bool detected = true;
+               if (magic_load(magic_cookie, NULL) != 0) {
+                       LYXERR(Debug::FILES, "isBinaryFile: "
+                               "Could not load magic database - "
+                               << magic_error(magic_cookie));
+                       detected = false;
+               } else {
+                       char const *charset = magic_file(magic_cookie,
+                                       filename.toFilesystemEncoding().c_str());
+                       isbinary = contains(charset, "binary");
+               }
+               magic_close(magic_cookie);
+               if (detected)
+                       return isbinary;
+       }
+#endif
+       // Try by looking for binary chars at the beginning of the file.
+       // Note that this is formally not correct, since count_bin_chars
+       // expects utf8, and the passed string can be anything: plain text
+       // in any encoding, or really binary data. In practice it works,
+       // since QString::fromUtf8() drops invalid utf8 sequences, and
+       // while the exact number may not be correct, we still get a high
+       // number for truly binary files.
+
+       ifstream ifs(filename.toFilesystemEncoding().c_str());
+       if (!ifs)
+               return isbinary;
+
+       // Maximum strings to read
+       int const max_count = 50;
+
+       // Maximum number of binary chars allowed
+       int const max_bin = 5;
+
+       int count = 0;
+       int binchars = 0;
+       string str;
+       while (count++ < max_count && !ifs.eof()) {
+               getline(ifs, str);
+               binchars += count_bin_chars(str);
+       }
+       return binchars > max_bin;
+}
+
+
 string const latex_path(string const & original_path,
                latex_path_extension extension,
                latex_path_dots dots)