xapian-dump: Rewrite to generate C code as output.

This was for some time testing, (to see how fast xapian could be
if we were strictly adding documents and not doing any other IO
or computation). The answer is that xapian is quite fast, (on
the order of 1000 documents per second).

xapian-dump.cc

@@ -39,15 +39,44 @@ using namespace std;
 
 vector<int> UNSERIALIZE;
 
+unsigned int MAX_TERMS = 0;
+
+static void
+print_escaped_string (const char *s)
+{
+    printf ("\"");
+
+    while (*s) {
+	if (*s == '"')
+	    printf ("\\");
+	printf ("%c", *s);
+	s++;
+    }
+
+    printf ("\"");
+}
+
 static void
 print_document_terms (Xapian::Document doc)
 {
-    Xapian::TermIterator i;
+    Xapian::TermIterator it;
+    unsigned int i;
 
-    printf ("    Terms:\n");
+    printf ("    {\n");
 
-    for (i = doc.termlist_begin (); i != doc.termlist_end (); i++)
+    for (it = doc.termlist_begin (), i = 0;
-	cout << "\t" << *i << endl;
+	 it != doc.termlist_end ();
+	 it++, i++)
+    {
+	printf ("        ");
+	print_escaped_string ((*it).c_str());
+	printf (",\n");
+    }
+
+    for ( ; i < MAX_TERMS; i++)
+	printf ("        \"\",\n");
+
+    printf ("    },\n");
 }
 
 static int
@@ -67,26 +96,25 @@ print_document_values (Xapian::Document doc)
     int value_no, value_int;
     double value_float;
 
-    printf ("    Values:\n");
-
     for (i = doc.values_begin (); i != doc.values_end (); i++) {
 	value_no = i.get_valueno();
 
-	cout << "\t" << i.get_valueno() << ": ";
+	printf ("    ");
 
 	if (vector_int_contains (UNSERIALIZE, value_no)) {
 	    value_float = Xapian::sortable_unserialise (*i);
 	    value_int = value_float;
 	    if (value_int == value_float)
-		cout << value_int;
+		printf ("%d", value_int);
 	    else
-		cout << value_float;
+		printf ("\"%f\"", value_float);
 	} else {
-	    cout << *i;
+	    print_escaped_string ((*i).c_str ());
 	}
 
-	cout << endl;
+	printf (",\n");
     }
+
 }
 
 static void
@@ -94,16 +122,17 @@ print_document (Xapian::Database db, Xapian::docid id)
 {
     Xapian::Document doc;
 
-    printf ("Document %u:\n", id);
+    printf ("{\n");
 
     doc = db.get_document (id);
 
-    printf ("    Data:\n");
+    printf ("    \"%s\",\n", doc.get_data ().c_str());
-    cout << "\t" << doc.get_data () << endl;
 
     print_document_terms (doc);
 
     print_document_values (doc);
+
+    printf ("},\n");
 }
 
 int
@@ -129,18 +158,43 @@ main (int argc, char *argv[])
 	UNSERIALIZE.push_back (atoi (argv[i]));
 
     try {
-
 	Xapian::Database db;
         Xapian::PostingIterator i;
 	Xapian::docid doc_id;
 
 	db = Xapian::Database (database_path);
+
+	for (i = db.postlist_begin (""); i != db.postlist_end (""); i++) {
+	    Xapian::Document doc;
+
+	    doc_id = *i;
+
+	    doc = db.get_document (doc_id);
+
+	    if (doc.termlist_count () > MAX_TERMS)
+		MAX_TERMS = doc.termlist_count ();
+	}
+
+	printf ("#define MAX_TERMS %d\n\n", MAX_TERMS);
+
+	printf ("typedef struct {\n"
+		"    char data[255];\n"
+		"    char terms[MAX_TERMS][255];\n"
+		"    char message_id[255];\n"
+		"    char thread_id[4096];\n"
+		"    time_t time;\n"
+		"} document_dump_t;\n\n");
+
+	printf ("document_dump_t dump[] = {\n");
+
 	for (i = db.postlist_begin (""); i != db.postlist_end (""); i++) {
 	    doc_id = *i;
 
 	    print_document (db, doc_id);
 	}
 
+	printf ("};\n");
+
     } catch (const Xapian::Error &error) {
 	cerr << "A Xapian exception occurred: " << error.get_msg () << endl;
 	exit (1);