WIP island determination; ocr resolver can make query to user

[ypp-sc-tools.db-test.git] / pctb / resolve.c

diff --git a/pctb/resolve.c b/pctb/resolve.c
new file mode 100644 (file)
index 0000000..052ec32
--- /dev/null
+++ b/pctb/resolve.c
@@ -0,0 +1,89 @@
+/*
+ * IPC to external resolver program
+ */
+/*
+ *  This is part of ypp-sc-tools, a set of third-party tools for assisting
+ *  players of Yohoho Puzzle Pirates.
+ * 
+ *  Copyright (C) 2009 Ian Jackson <ijackson@chiark.greenend.org.uk>
+ * 
+ *  This program is free 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 3 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
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ *  Yohoho and Puzzle Pirates are probably trademarks of Three Rings and
+ *  are used without permission.  This program is not endorsed or
+ *  sponsored by Three Rings.
+ */
+
+#include "ocr.h"
+
+static FILE *resolver;
+static pid_t resolver_pid;
+static int resolver_done;
+
+FILE *resolve_start(void) {
+  int jobpipe[2],donepipe[2];
+
+  if (!o_resolver) return 0;
+
+  if (!resolver) {
+    sysassert(! pipe(jobpipe) );
+    sysassert(! pipe(donepipe) );
+    resolver_pid= fork();
+    sysassert(resolver_pid!=-1);
+    if (!resolver_pid) {
+      sysassert( dup2(jobpipe[0],0) ==0 );
+      sysassert(! close(jobpipe[1]) );
+      sysassert(! close(donepipe[0]) );
+      /* we know donepipe[1] is >= 4 and we have dealt with all the others
+       * so we aren't in any danger of overwriting some other fd 4: */
+      sysassert( dup2(donepipe[1],4) ==4 );
+      execlp(o_resolver, o_resolver,
+            DEBUGP(callout) ? "--debug" : "--noop-arg",
+            "--automatic-1",
+            (char*)0);
+      sysassert(!"execlp ocr-resolver failed");
+    }
+    sysassert(! close(jobpipe[0]) );
+    sysassert(! close(donepipe[1]) );
+    resolver= fdopen(jobpipe[1],"w"); sysassert(resolver);
+    resolver_done= donepipe[0];
+  }
+  return resolver;
+}
+
+void resolve_finish(void) {
+  char cb;
+  
+  sysassert(!ferror(resolver));
+  sysassert(!fflush(resolver));
+
+  sysassert(resolver);
+
+  int r;
+  for (;;) {
+    r= read(resolver_done,&cb,1);
+    if (r==-1) { sysassert(errno==EINTR); continue; }
+    break;
+  }
+
+  if (r==0) {
+    waitpid_check_exitstatus(resolver_pid, "character resolver");
+    fclose(resolver);
+    close(resolver_done);
+    resolver= 0;
+  } else {
+    assert(r==1);
+    sysassert(cb==0);
+  }
+}