common/admin_socket: simplify command routing

Back in e30e937c89 we made it possible to
route a command via any prefix. This worked when we wanted to pass
arguments but were just dealing with a vector<string>.  These days we have
an actual prefix followed by named arguments, so we don't need this
ad hoc routing.

Derive the prefix from the cmddesc at registration time, and match that
explicitly against the prefix at execution time.

Signed-off-by: Sage Weil <sage@redhat.com>

src/common/admin_socket.cc

@@ -397,10 +397,10 @@ int AdminSocket::execute_command(const std::vector<std::string>& cmdvec,
     ldout(m_cct, 0) << "AdminSocket: " << errss.str() << dendl;
     return false;
   }
-  string match;
+  string prefix;
   try {
     cmd_getval(m_cct, cmdmap, "format", format);
-    cmd_getval(m_cct, cmdmap, "prefix", match);
+    cmd_getval(m_cct, cmdmap, "prefix", prefix);
   } catch (const bad_cmd_get& e) {
     return false;
   }
@@ -410,21 +410,7 @@ int AdminSocket::execute_command(const std::vector<std::string>& cmdvec,
 
   std::unique_lock l(lock);
   decltype(hooks)::iterator p;
-  while (match.size()) {
-    p = hooks.find(match);
-    if (p != hooks.cend())
-      break;
-
-    // drop right-most word
-    size_t pos = match.rfind(' ');
-    if (pos == std::string::npos) {
-      match.clear();  // we fail
-      break;
-    } else {
-      match.resize(pos);
-    }
-  }
-
+  p = hooks.find(prefix);
   if (p == hooks.cend()) {
     lderr(m_cct) << "AdminSocket: request '" << cmdvec
 		 << "' not defined" << dendl;
@@ -436,20 +422,20 @@ int AdminSocket::execute_command(const std::vector<std::string>& cmdvec,
   // and set in_hook to allow unregister to wait for us before
   // removing this hook.
   in_hook = true;
-  auto match_hook = p->second.hook;
+  auto hook = p->second.hook;
   l.unlock();
-  bool success = (validate(match, cmdmap, out) &&
-      match_hook->call(match, cmdmap, format, out));
+  bool success = (validate(prefix, cmdmap, out) &&
+      hook->call(prefix, cmdmap, format, out));
   l.lock();
   in_hook = false;
   in_hook_cond.notify_all();
   if (!success) {
-    ldout(m_cct, 0) << "AdminSocket: request '" << match
-		    << "' to " << match_hook << " failed" << dendl;
+    ldout(m_cct, 0) << "AdminSocket: request '" << prefix
+		    << "' to " << hook << " failed" << dendl;
     out.append("failed");
   } else {
-    ldout(m_cct, 5) << "AdminSocket: request '" << match
-        << "' to " << match_hook
+    ldout(m_cct, 5) << "AdminSocket: request '" << prefix
+        << "' to " << hook
         << " returned " << out.length() << " bytes" << dendl;
   }
   return true;
@@ -464,12 +450,12 @@ void AdminSocket::queue_tell_command(ref_t<MCommand> m)
 }
 
 
-bool AdminSocket::validate(const std::string& command,
+bool AdminSocket::validate(const std::string& prefix,
 			   const cmdmap_t& cmdmap,
 			   bufferlist& out) const
 {
   stringstream os;
-  if (validate_cmd(m_cct, hooks.at(command).desc, cmdmap, os)) {
+  if (validate_cmd(m_cct, hooks.at(prefix).desc, cmdmap, os)) {
     return true;
   } else {
     out.append(os);
@@ -484,17 +470,18 @@ int AdminSocket::register_command(std::string_view command,
 {
   int ret;
   std::unique_lock l(lock);
-  auto i = hooks.find(command);
+  string prefix = cmddesc_get_prefix(cmddesc);
+  auto i = hooks.find(prefix);
   if (i != hooks.cend()) {
-    ldout(m_cct, 5) << "register_command " << command << " hook " << hook
+    ldout(m_cct, 5) << "register_command " << prefix << " hook " << hook
 		    << " EEXIST" << dendl;
     ret = -EEXIST;
   } else {
-    ldout(m_cct, 5) << "register_command " << command << " hook " << hook
+    ldout(m_cct, 5) << "register_command " << prefix << " hook " << hook
 		    << dendl;
     hooks.emplace_hint(i,
 		       std::piecewise_construct,
-		       std::forward_as_tuple(command),
+		       std::forward_as_tuple(prefix),
 		       std::forward_as_tuple(hook, cmddesc, help));
     ret = 0;
   }

src/common/cmdparse.cc

@@ -22,9 +22,10 @@
  * Given a cmddesc like "foo baz name=bar,type=CephString",
  * return the prefix "foo baz".
  */
-std::string cmddesc_get_prefix(const std::string &cmddesc)
+std::string cmddesc_get_prefix(const std::string_view &cmddesc)
 {
-  stringstream ss(cmddesc);
+  string tmp(cmddesc); // FIXME: stringstream ctor can't take string_view :(
+  stringstream ss(tmp);
   std::string word;
   std::ostringstream result;
   bool first = true;

src/common/cmdparse.h

@@ -22,7 +22,7 @@ typedef boost::variant<std::string,
 		       std::vector<double>>  cmd_vartype;
 typedef std::map<std::string, cmd_vartype, std::less<>> cmdmap_t;
 
-std::string cmddesc_get_prefix(const std::string &cmddesc);
+std::string cmddesc_get_prefix(const std::string_view &cmddesc);
 std::string cmddesc_get_prenautilus_compat(const std::string &cmddesc);
 void dump_cmd_to_json(ceph::Formatter *f, uint64_t features,
                       const std::string& cmd);