[Qemu-devel] [PATCH v2] Sort the help info shown in monitor at runtime

[Wayne Xia <xiawenc@linux.vnet.ibm.com>]

Introduced two queues to save sorted command list in it. As a result, command
help and help info would show a more friendly sorted command list.
For eg:
(qemu)help
acl_add
acl_policy
acl_remove
acl_reset
acl_show
balloon
block_passwd
...
the command list is sorted.

v2: write sorted command list back to original array.

Signed-off-by: Wayne Xia <xiawenc@linux.vnet.ibm.com>
---
 monitor.c |  113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 109 insertions(+), 4 deletions(-)

diff --git a/monitor.c b/monitor.c
index 31b212a..122f950 100644
--- a/monitor.c
+++ b/monitor.c
@@ -66,6 +66,7 @@
 #include "memory.h"
 #include "qmp-commands.h"
 #include "hmp.h"
+#include "qemu-queue.h"
 
 //#define DEBUG
 //#define DEBUG_COMPLETION
@@ -128,6 +129,18 @@ typedef struct mon_cmd_t {
     int flags;
 } mon_cmd_t;
 
+/* queue structure used for runtime sorting */
+struct HelpCmdElem {
+    QTAILQ_ENTRY(HelpCmdElem) entry;
+    mon_cmd_t cmd_copy;
+};
+
+typedef struct HelpCmdElem HelpCmdElem;
+
+QTAILQ_HEAD(HelpCmdQueue, HelpCmdElem);
+
+typedef struct HelpCmdQueue HelpCmdQueue;
+
 /* file descriptors passed via SCM_RIGHTS */
 typedef struct mon_fd_t mon_fd_t;
 struct mon_fd_t {
@@ -195,8 +208,8 @@ static inline int mon_print_count_get(const Monitor *mon) { return 0; }
 
 static QLIST_HEAD(mon_list, Monitor) mon_list;
 
-static const mon_cmd_t mon_cmds[];
-static const mon_cmd_t info_cmds[];
+static mon_cmd_t mon_cmds[];
+static mon_cmd_t info_cmds[];
 
 static const mon_cmd_t qmp_cmds[];
 static const mon_cmd_t qmp_query_cmds[];
@@ -2726,13 +2739,14 @@ int monitor_get_fd(Monitor *mon, const char *fdname)
     return -1;
 }
 
-static const mon_cmd_t mon_cmds[] = {
+/* mon_cmds and info_cmds would be sorted at runtime */
+static mon_cmd_t mon_cmds[] = {
 #include "hmp-commands.h"
     { NULL, NULL, },
 };
 
 /* Please update hmp-commands.hx when adding or changing commands */
-static const mon_cmd_t info_cmds[] = {
+static mon_cmd_t info_cmds[] = {
     {
         .name       = "version",
         .args_type  = "",
@@ -5068,6 +5082,94 @@ static void monitor_event(void *opaque, int event)
     }
 }
 
+static int cmdlist_sortto_queue(const mon_cmd_t *cmdlist,
+                                HelpCmdQueue **pqueue)
+{
+    const mon_cmd_t *cmd = NULL;
+    HelpCmdElem *elem = NULL;
+    HelpCmdElem *newelem = NULL;
+    HelpCmdElem *next = NULL;
+    HelpCmdQueue *cmdqueue = NULL;
+    int cmpret1, cmpret2;
+
+    cmdqueue = g_malloc(sizeof(HelpCmdQueue));
+    if (cmdqueue == NULL) {
+        return -1;
+    }
+
+    for (cmd = cmdlist; cmd->name != NULL; cmd++) {
+        newelem = NULL;
+        newelem = g_malloc(sizeof(HelpCmdElem));
+        if (newelem == NULL) {
+            return -1;
+        }
+        newelem->cmd_copy = *cmd;
+
+        if (QTAILQ_EMPTY(cmdqueue)) {
+            QTAILQ_INSERT_HEAD(cmdqueue, newelem, entry);
+            continue;
+        }
+        QTAILQ_FOREACH_SAFE(elem, cmdqueue, entry, next) {
+            /* search for proper postion */
+            cmpret1 = strcmp(cmd->name, elem->cmd_copy.name);
+            if (next == NULL) {
+                if (cmpret1 >= 0) {
+                    QTAILQ_INSERT_TAIL(cmdqueue, newelem, entry);
+                } else {
+                    QTAILQ_INSERT_HEAD(cmdqueue, newelem, entry);
+                }
+                break;
+            } else {
+                cmpret2 = strcmp(cmd->name, next->cmd_copy.name);
+            }
+            if ((cmpret1 >= 0) && (cmpret2 <= 0)) {
+                QTAILQ_INSERT_AFTER(cmdqueue, elem, newelem, entry);
+                break;
+            }
+        }
+    }
+    *pqueue = cmdqueue;
+    return 1;
+}
+
+static void queue_to_cmdlist(HelpCmdQueue **pqueue,
+                                mon_cmd_t *cmdlist)
+{
+    HelpCmdElem *elem = NULL;
+    HelpCmdElem *next = NULL;
+    HelpCmdQueue *cmdqueue = *pqueue;
+    mon_cmd_t *pcmdlist = cmdlist;
+
+    QTAILQ_FOREACH_SAFE(elem, cmdqueue, entry, next) {
+        *(pcmdlist++) = elem->cmd_copy;
+        QTAILQ_REMOVE(cmdqueue, elem, entry);
+        g_free(elem);
+    }
+    g_free(cmdqueue);
+    *pqueue = NULL;
+}
+
+static void sortcmdlist(void)
+{
+    HelpCmdQueue *mon_cmds_queue = NULL;
+    HelpCmdQueue *info_cmds_queue = NULL;
+    int ret;
+
+    ret = cmdlist_sortto_queue(mon_cmds, &mon_cmds_queue);
+    if (ret < 0) {
+        printf("error in initilize mon cmd queue, return is %d.\n", ret);
+        return;
+    }
+    queue_to_cmdlist(&mon_cmds_queue, mon_cmds);
+
+    ret = cmdlist_sortto_queue(info_cmds, &info_cmds_queue);
+    if (ret < 0) {
+        printf("error in initilize info cmd queue, return is %d.\n", ret);
+        return;
+    }
+    queue_to_cmdlist(&info_cmds_queue, info_cmds);
+}
+
 
 /*
  * Local variables:
@@ -5110,6 +5212,9 @@ void monitor_init(CharDriverState *chr, int flags)
     QLIST_INSERT_HEAD(&mon_list, mon, entry);
     if (!default_mon || (flags & MONITOR_IS_DEFAULT))
         default_mon = mon;
+
+    sortcmdlist();
+
 }
 
 static void bdrv_password_cb(Monitor *mon, const char *password, void *opaque)
-- 
1.7.6