xapian-applications/omega/handler_libreofficekit.cc

   1 /** @file
   2  * @brief Extract text and metadata using LibreOfficeKit
   3  */
   4 /* Copyright (C) 2014-2023 Olly Betts
   5  *
   6  * This Source Code Form is subject to the terms of the Mozilla Public
   7  * License, v. 2.0. If a copy of the MPL was not distributed with this
   8  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   9  */
  10
  11 #include <config.h>
  12
  13 #include "handler.h"
  14
  15 #include "htmlparser.h"
  16 #include "loadfile.h"
  17 #include "tmpdir.h"
  18 #include "urlencode.h"
  19
  20 using namespace std;
  21
  22 #include <climits>
  23 #include <cstdlib>
  24 #include <exception>
  25 #include <iostream>
  26 #include <memory>
  27
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <dirent.h>
  31 #include <unistd.h>
  32 #include "safesysexits.h"
  33
  34 #define LOK_USE_UNSTABLE_API // So we can use lok::Document::getParts().
  35 #include <LibreOfficeKit/LibreOfficeKit.hxx>
  36
  37 using namespace std;
  38 using namespace lok;
  39
  40 // Install location for Debian packages (also Fedora on 32-bit architectures):
  41 #define LO_PATH_DEBIAN "/usr/lib/libreoffice/program"
  42
  43 // Install location for Fedora packages on 64-bit architectures:
  44 #define LO_PATH_FEDORA64 "/usr/lib64/libreoffice/program"
  45
  46 // Install location on macOS.  May not actually work there currently though,
  47 // see: https://gitlab.com/ojwb/lloconv/-/issues/11
  48 #define LO_PATH_MACOS "/Applications/LibreOffice.app/Contents/Frameworks"
  49
  50 // Find a LibreOffice installation to use.
  51 static const char*
  52 get_lo_path()
  53 {
  54     const char* lo_path = getenv("LO_PATH");
  55     if (lo_path) return lo_path;
  56
  57     struct stat sb;
  58 #define CHECK_DIR(P) if (stat(P"/versionrc", &sb) == 0 && S_ISREG(sb.st_mode)) return P
  59 #ifdef __APPLE__
  60     CHECK_DIR(LO_PATH_MACOS);
  61 #else
  62     CHECK_DIR(LO_PATH_DEBIAN);
  63     if constexpr(sizeof(void*) > 4) {
  64         CHECK_DIR(LO_PATH_FEDORA64);
  65     }
  66 #endif
  67
  68     // Check install locations for .deb files from libreoffice.org,
  69     // e.g. /opt/libreoffice6.3/program
  70     DIR* opt = opendir("/opt");
  71     if (opt) {
  72         // We require at least LibreOffice 4.3.
  73         unsigned long best_major = 4;
  74         unsigned long best_minor = 2;
  75         static string best_rc;
  76         struct dirent* d;
  77         while ((d = readdir(opt))) {
  78 #ifdef DT_DIR
  79             // Opportunistically skip non-directories if we can spot them
  80             // just by looking at d_type.
  81             if (d->d_type != DT_DIR && d->d_type != DT_UNKNOWN) {
  82                 continue;
  83             }
  84 #endif
  85             if (memcmp(d->d_name, "libreoffice", strlen("libreoffice")) != 0) {
  86                 continue;
  87             }
  88
  89             char* p = d->d_name + strlen("libreoffice");
  90             unsigned long major = strtoul(p, &p, 10);
  91             if (major == ULONG_MAX) continue;
  92             unsigned long minor = 0;
  93             if (*p == '.') {
  94                 minor = strtoul(p + 1, &p, 10);
  95                 if (minor == ULONG_MAX) continue;
  96
  97                 string rc = "/opt/";
  98                 rc += d->d_name;
  99                 rc += "/program";
 100                 if (stat((rc + "/versionrc").c_str(), &sb) != 0 ||
 101                     !S_ISREG(sb.st_mode)) {
 102                     continue;
 103                 }
 104
 105                 if (major > best_major ||
 106                     (major == best_major && minor > best_minor)) {
 107                     best_major = major;
 108                     best_minor = minor;
 109                     best_rc = std::move(rc);
 110                 }
 111             }
 112         }
 113         closedir(opt);
 114         if (!best_rc.empty()) {
 115             return best_rc.c_str();
 116         }
 117     }
 118
 119     cerr << "LibreOffice install not found\n"
 120         "Set LO_PATH in the environment to the 'program' directory - e.g.:\n"
 121         "LO_PATH=/opt/libreoffice/program\n"
 122         "export LO_PATH\n";
 123     _Exit(EX_UNAVAILABLE);
 124 }
 125
 126 static string output_file;
 127 static string output_url;
 128
 129 static Office* llo;
 130
 131 bool
 132 initialise()
 133 {
 134     output_file = get_tmpfile("tmp.html");
 135     if (output_file.empty()) {
 136         cerr << "Couldn't create temporary directory\n";
 137         return false;
 138     }
 139     url_encode_path(output_url, output_file);
 140
 141     const char* lo_path = get_lo_path();
 142     llo = lok_cpp_init(lo_path);
 143     if (!llo) {
 144         cerr << "Failed to initialise LibreOfficeKit\n";
 145         return false;
 146     }
 147     return true;
 148 }
 149
 150 void
 151 extract(const string& filename, const string&)
 152 try {
 153     const char* format = "html"; // FIXME or xhtml
 154     const char* options = "SkipImages";
 155     string input_url;
 156     url_encode_path(input_url, filename);
 157     unique_ptr<Document> lodoc(llo->documentLoad(input_url.c_str(), options));
 158     if (!lodoc.get()) {
 159         const char* errmsg = llo->getError();
 160         send_field(FIELD_ERROR, errmsg ? errmsg : "Failed to load document");
 161         return;
 162     }
 163
 164     if (!lodoc->saveAs(output_url.c_str(), format, options)) {
 165         const char* errmsg = llo->getError();
 166         send_field(FIELD_ERROR, errmsg ? errmsg : "Failed to load export");
 167         return;
 168     }
 169
 170     string html;
 171     if (!load_file(output_file, html)) {
 172         unlink(output_file.c_str());
 173         send_field(FIELD_ERROR, "Failed to load LibreOffice HTML output");
 174         return;
 175     }
 176     HtmlParser p;
 177     p.ignore_metarobots();
 178     p.parse(html, "utf-8", true);
 179     unlink(output_file.c_str());
 180     send_field(FIELD_BODY, p.dump);
 181     send_field(FIELD_TITLE, p.title);
 182     send_field(FIELD_KEYWORDS, p.keywords);
 183     send_field(FIELD_KEYWORDS, p.topic);
 184     send_field(FIELD_AUTHOR, p.author);
 185     send_field_created_date(p.created);
 186     // The documentation comment in LibreOfficeKit.hxx says this method
 187     // returns a count of "individual sheets in a Calc, or slides in Impress,
 188     // and has no relevance for Writer" but it actually seems to return a
 189     // page count for writer documents.
 190     send_field_page_count(lodoc->getParts());
 191 } catch (const exception& e) {
 192     send_field(FIELD_ERROR, e.what());
 193 }