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Diffstat (limited to 'lib/basic-imgstream.cc')
| -rw-r--r-- | lib/basic-imgstream.cc | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/lib/basic-imgstream.cc b/lib/basic-imgstream.cc new file mode 100644 index 0000000..9b7aea8 --- /dev/null +++ b/lib/basic-imgstream.cc @@ -0,0 +1,301 @@ +// basic-imgstream.cc -- the mother of all image streams +// Copyright (C) 2008, 2009 SEIKO EPSON CORPORATION +// +// This file is part of the 'iscan' program. +// +// The 'iscan' program is free-ish software. +// You can redistribute it and/or modify it under the terms of the GNU +// General Public License as published by the Free Software Foundation; +// either version 2 of the License or at your option any later version. +// +// This program is distributed in the hope that it will be useful, but +// WITHOUT ANY WARRANTY; without even the implied warranty of FITNESS +// FOR A PARTICULAR PURPOSE or MERCHANTABILITY. +// See the GNU General Public License for more details. +// +// You should have received a verbatim copy of the GNU General Public +// License along with this program; if not, write to: +// +// Free Software Foundation, Inc. +// 59 Temple Place, Suite 330 +// Boston, MA 02111-1307 USA +// +// As a special exception, the copyright holders give permission +// to link the code of this program with the esmod library and +// distribute linked combinations including the two. You must obey +// the GNU General Public License in all respects for all of the +// code used other then esmod. + + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "basic-imgstream.hh" + +#include <cstdlib> +#include <argz.h> + +namespace iscan +{ + +#if __GLIBC_PREREQ(2, 10) + typedef const dirent** dirtype; +#else + typedef const void* dirtype; +#endif + + basic_imgstream::basic_imgstream (void) + : _h_sz (0), _v_sz (0), _hres (0), _vres (0), _bits (0), _cspc (NONE) + { + } + + basic_imgstream::~basic_imgstream (void) + { + } + + basic_imgstream& + basic_imgstream::flush (void) + { + return *this; + } + + basic_imgstream& + basic_imgstream::size (size_type h_sz, size_type v_sz) + { + _h_sz = h_sz; + _v_sz = v_sz; + return *this; + } + + basic_imgstream& + basic_imgstream::resolution (size_type hres, size_type vres) + { + _hres = hres; + _vres = vres; + return *this; + } + + basic_imgstream& + basic_imgstream::depth (size_type bits) + { + _bits = bits; + return *this; + } + + basic_imgstream& + basic_imgstream::colour (colour_space space) + { + _cspc = space; + return *this; + } + + + basic_imgstream::dl_handle + basic_imgstream::dlopen (const char *libname, + bool (*validate) (lt_dlhandle)) + { + if (0 != lt_dlinit ()) + { + throw runtime_error (lt_dlerror ()); + } + + dl_handle lib = find_dlopen (libname, validate); + if (!lib) + { + lt_dlexit (); + throw runtime_error ("no usable library found"); + } + + return lib; + } + + basic_imgstream::dl_ptr + basic_imgstream::dlsym (dl_handle lib, const char *funcname) + { + return lt_dlsym (lib, funcname); + } + + int + basic_imgstream::dlclose (dl_handle lib) + { + return lt_dlclose (lib); + } + + // forward declarations + static int reversionsort (dirtype, dirtype); + int selector (const dirent *); + + //! + /*! A number of distributions seems to have switched to a policy where + the lib*.so files are provided by their -devel packages. Moreover, + the typical workstation install does not include such packages and + lt_dlopenext() will understandably have trouble finding your lib*. + + This function is a fallback for such cases. It will look for your + library in the exact same places as lt_dlopenext(), but with this + difference that it will try to open any file that matches lib*.so, + starting with the one with the highest version number. + + Actually, it is just as smart lt_dlopenext() and uses the correct + shared library extension for your platform. However, it does not + try libtool's .la extension. + + The general policy for memory allocation and access problems is to + ignore them and muddle on or return the current result rightaway. + + This function returns NULL if no suitable library could be found + and a handle to library otherwise. + */ + basic_imgstream::dl_handle + basic_imgstream::find_dlopen (const char *libname, + bool (*validate) (lt_dlhandle)) + { + using std::bad_alloc; + using std::string; + + dl_handle result = NULL; + + try + { // prepping the selector() + char *name = new char[strlen (libname) + + strlen (LT_MODULE_EXT) + 1]; + name = strcpy (name, libname); + name = strcat (name, LT_MODULE_EXT); + + _libname = name; // deleting _libname below, never mind + // that name goes out of scope here + } + catch (bad_alloc& oops) + { + return result; + } + + char *pathz = NULL; + size_t length = 0; + bool is_pathz_ok = true; + { // set up a library search path like + // that used by lt_dlopen() + int delimiter = ':'; + + const char *path = NULL; + + if ((path = lt_dlgetsearchpath ()) + && 0 != argz_add_sep (&pathz, &length, path, delimiter)) + { + is_pathz_ok = false; + } + if ((path = getenv ("LTDL_LIBRARY_PATH")) + && 0 != argz_add_sep (&pathz, &length, path, delimiter)) + { + is_pathz_ok = false; + } + if ((path = getenv (LT_MODULE_PATH_VAR)) + && 0 != argz_add_sep (&pathz, &length, path, delimiter)) + { + is_pathz_ok = false; + } + if ("x86_64" == string (ISCAN_HOST_CPU) + && (path = "/usr/local/lib64:/usr/lib64:/lib64") + && 0 != argz_add_sep (&pathz, &length, path, delimiter)) + { + is_pathz_ok = false; + } + // Kludge for multiarch support introduced in Ubuntu 11.04 + if ("x86_64" == string (ISCAN_HOST_CPU)) + { + if ((path = "/usr/lib/x86_64-linux-gnu:/lib/x86_64-linux-gnu") + && 0 != argz_add_sep (&pathz, &length, path, delimiter)) + { + is_pathz_ok = false; + } + } + else + { + if ((path = "/usr/lib/i386-linux-gnu:/lib/i386-linux-gnu") + && 0 != argz_add_sep (&pathz, &length, path, delimiter)) + { + is_pathz_ok = false; + } + } + if ((path = LT_DLSEARCH_PATH) + && 0 != argz_add_sep (&pathz, &length, path, delimiter)) + { + is_pathz_ok = false; + } + } + + if (is_pathz_ok) + { // go fetch! + const char *dir_name = NULL; + while (!result + && (dir_name = argz_next (pathz, length, dir_name))) + { + struct dirent **match = NULL; + int count = scandir (dir_name, &match, selector, reversionsort); + + for (int i = 0; !result && i < count; ++i) + { + + const char *file_name = match[i]->d_name; + try + { + char *abs_file_name + = new char[strlen (dir_name) + strlen ("/") + + strlen (file_name) + 1]; + strcpy (abs_file_name, dir_name); + strcat (abs_file_name, "/"); + strcat (abs_file_name, file_name); + + result = lt_dlopen (abs_file_name); + if (validate && !validate (result)) + { + lt_dlclose (result); + result = NULL; + } + delete [] abs_file_name; + } + catch (bad_alloc& oops) + { + // just ignore and continue with the next match + } + free (match[i]); + } + if (match) free (match); // malloc'd by scandir() + } + } + + delete [] _libname; // we new'd a name for our selector() + free (pathz); // malloc'd by argz_add_sep() + + return result; + } + + //! Library name we are looking for. + /*! The scandir() API does not allow for passing arbitrary data to the + selector(). We use this variable to work around that limitation. + + Note that this makes users of selector() thread unsafe. + */ + const char *basic_imgstream::_libname = NULL; + + //! Selects relevant library filenames. + /*! Returns true if the leading part of the directory entry's file + name matches the library name we are looking for. The file name + may contain trailing version information which is ignored. + */ + int + selector (const dirent *dir) + { + return (0 == strncmp (dir->d_name, basic_imgstream::_libname, + strlen (basic_imgstream::_libname))); + } + + //! The C library's versionsort() function in reverse. + static int + reversionsort (dirtype a, dirtype b) + { + return versionsort (b, a); + } + +} // namespace iscan |