fish: Use a perfect hash for faster command lookups.

Existing command lookups are approx O(n^2).  Replace this
with a perfect hash implementation which should be a lot
faster.

1 files changed, 46 insertions, 0 deletions

diff --git a/fish/cmds_gperf.h b/fish/cmds_gperf.h
new file mode 100644
index 00000000..92bd6070
--- /dev/null
+++ b/fish/cmds_gperf.h
@@ -0,0 +1,46 @@
+/* libguestfs - guestfish shell
+ * Copyright (C) 2010 Red Hat Inc.
+ *
+ * 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 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
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef FISH_CMDS_GPERF_H
+#define FISH_CMDS_GPERF_H
+
+/* There is one of these structures for each individual command that
+ * guestfish can execute.
+ */
+struct command_entry {
+  /* These fields are passed to pod2text to implement the online help. */
+  const char *name;
+  const char *shortdesc;
+  const char *podbody;
+
+  /* The run_* function. */
+  int (*run) (const char *cmd, size_t argc, char *argv[]);
+};
+
+/* Command table used by the gperf-generated lookup function.
+ * Multiple rows in this table can and do point to a single command
+ * entry.  This is used to implement aliases.
+ */
+struct command_table {
+  char *name;
+  struct command_entry *entry;
+};
+
+const struct command_table *lookup_fish_command (register const char *str, register unsigned int len);
+
+#endif /* FISH_CMDS_GPERF_H */