Merge pull request #2331 from splinterofchaos/serverlisten

vimL: serverlisten({addr}), list(), and stop({addr})

8 files changed, 243 insertions, 40 deletions

diff --git a/config/CMakeLists.txt b/config/CMakeLists.txt
index 0d3ef62297..ed1f422070 100644
--- a/config/CMakeLists.txt
+++ b/config/CMakeLists.txt
@@ -58,6 +58,7 @@ check_function_exists(setenv HAVE_SETENV)
 if(NOT HAVE_SETENV)
   message(SEND_ERROR "setenv() function not found on your system.")
 endif()
+check_function_exists(unsetenv HAVE_UNSETENV)
 check_function_exists(setpgid HAVE_SETPGID)
 check_function_exists(setsid HAVE_SETSID)
 check_function_exists(sigaction HAVE_SIGACTION)
diff --git a/config/config.h.in b/config/config.h.in
index 04db12fbe3..9b2abfa19d 100644
--- a/config/config.h.in
+++ b/config/config.h.in
@@ -37,6 +37,7 @@
 // TODO: add proper cmake check
 // #define HAVE_SELINUX 1
 #cmakedefine HAVE_SETENV
+#cmakedefine HAVE_UNSETENV
 #cmakedefine HAVE_SETPGID
 #cmakedefine HAVE_SETSID
 #cmakedefine HAVE_SIGACTION
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index fc4bebbd6e..a9ed4acb19 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -5373,13 +5373,25 @@ server2client( {clientid}, {string})			*server2client()*
 			:echo server2client(expand("<client>"), "HELLO")
 <
 serverlist()					*serverlist()*
-		Return a list of available server names, one per line.
-		When there are no servers or the information is not available
-		an empty string is returned.  See also |clientserver|.
-		{only available when compiled with the |+clientserver| feature}
+		Returns a list of available server names in a list.
+		When there are no servers an empty string is returned.
 		Example: >
 			:echo serverlist()
 <
+serverlisten([{address}])				*serverlisten()*
+		Opens a Unix or TCP socket at {address} for clients to connect
+		to and returns {address}. If no address is given, it is
+		equivalent to >
+			:call serverlisten(tempname())
+< 		If |$NVIM_LISTEN_ADDRESS| is not set, it will be set to
+		{address}.
+
+serverstop({address})					*serverstop()*
+		Closes the Unix or TCP socket at {address}. Does nothing if
+		{address} is empty, or does not refer to a server. If
+		{address} equals |$NVIM_LISTEN_ADDRESS|, the listen address
+		will be unset.
+
 setbufvar({expr}, {varname}, {val})			*setbufvar()*
 		Set option or local variable {varname} in buffer {expr} to
 		{val}.
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 1616bf60e2..1dab9df9cb 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -87,6 +87,7 @@
 #include "nvim/os/rstream_defs.h"
 #include "nvim/os/time.h"
 #include "nvim/msgpack_rpc/channel.h"
+#include "nvim/msgpack_rpc/server.h"
 #include "nvim/api/private/helpers.h"
 #include "nvim/api/vim.h"
 #include "nvim/os/dl.h"
@@ -6605,6 +6606,9 @@ static struct fst {
   {"searchpair",      3, 7, f_searchpair},
   {"searchpairpos",   3, 7, f_searchpairpos},
   {"searchpos",       1, 4, f_searchpos},
+  {"serverlist",      0, 0, f_serverlist},
+  {"serverstart",     0, 1, f_serverstart},
+  {"serverstop",      1, 1, f_serverstop},
   {"setbufvar",       3, 3, f_setbufvar},
   {"setcmdpos",       1, 1, f_setcmdpos},
   {"setline",         2, 2, f_setline},
@@ -13292,6 +13296,69 @@ static void f_searchpos(typval_T *argvars, typval_T *rettv)
     list_append_number(rettv->vval.v_list, (varnumber_T)n);
 }
 
+/// "serverlist()" function
+static void f_serverlist(typval_T *argvars, typval_T *rettv)
+{
+  size_t n;
+  char **addrs = server_address_list(&n);
+
+  // Copy addrs into a linked list.
+  list_T *l = rettv_list_alloc(rettv);
+  for (size_t i = 0; i < n; i++) {
+    listitem_T *li = listitem_alloc();
+    li->li_tv.v_type = VAR_STRING;
+    li->li_tv.v_lock = 0;
+    li->li_tv.vval.v_string = (char_u *) addrs[i];
+    list_append(l, li);
+  }
+  xfree(addrs);
+}
+
+/// "serverstart()" function
+static void f_serverstart(typval_T *argvars, typval_T *rettv)
+{
+  rettv->v_type = VAR_STRING;
+  rettv->vval.v_string = NULL;  // Will hold the address of the new server.
+
+  if (check_restricted() || check_secure()) {
+    return;
+  }
+
+  // If the user supplied an address, use it, otherwise use a temp.
+  if (argvars[0].v_type != VAR_UNKNOWN) {
+    if (argvars[0].v_type != VAR_STRING) {
+      EMSG(_(e_invarg));
+      return;
+    } else {
+      rettv->vval.v_string = vim_strsave(get_tv_string(argvars));
+    }
+  } else {
+    rettv->vval.v_string = vim_tempname();
+  }
+
+  int result = server_start((char *) rettv->vval.v_string);
+  if (result != 0) {
+    EMSG2("Failed to start server: %s", uv_strerror(result));
+  }
+}
+
+/// "serverstop()" function
+static void f_serverstop(typval_T *argvars, typval_T *rettv)
+{
+  if (check_restricted() || check_secure()) {
+    return;
+  }
+
+  if (argvars[0].v_type == VAR_UNKNOWN || argvars[0].v_type != VAR_STRING) {
+    EMSG(_(e_invarg));
+    return;
+  }
+
+  if (argvars[0].vval.v_string) {
+    server_stop((char *) argvars[0].vval.v_string);
+  }
+}
+
 /*
  * "setbufvar()" function
  */
diff --git a/src/nvim/msgpack_rpc/server.c b/src/nvim/msgpack_rpc/server.c
index c03531ca0c..8fb2902b0b 100644
--- a/src/nvim/msgpack_rpc/server.c
+++ b/src/nvim/msgpack_rpc/server.c
@@ -9,11 +9,11 @@
 #include "nvim/msgpack_rpc/server.h"
 #include "nvim/os/os.h"
 #include "nvim/ascii.h"
+#include "nvim/garray.h"
 #include "nvim/vim.h"
 #include "nvim/memory.h"
 #include "nvim/log.h"
 #include "nvim/tempfile.h"
-#include "nvim/map.h"
 #include "nvim/path.h"
 
 #define MAX_CONNECTIONS 32
@@ -27,6 +27,9 @@ typedef enum {
 } ServerType;
 
 typedef struct {
+  // The address of a pipe, or string value of a tcp address.
+  char addr[ADDRESS_MAX_SIZE];
+
   // Type of the union below
   ServerType type;
 
@@ -38,12 +41,11 @@ typedef struct {
     } tcp;
     struct {
       uv_pipe_t handle;
-      char addr[ADDRESS_MAX_SIZE];
     } pipe;
   } socket;
 } Server;
 
-static PMap(cstr_t) *servers = NULL;
+static garray_T servers = GA_EMPTY_INIT_VALUE;
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "msgpack_rpc/server.c.generated.h"
@@ -52,33 +54,40 @@ static PMap(cstr_t) *servers = NULL;
 /// Initializes the module
 bool server_init(void)
 {
-  servers = pmap_new(cstr_t)();
+  ga_init(&servers, sizeof(Server *), 1);
 
-  if (!os_getenv(LISTEN_ADDRESS_ENV_VAR)) {
-    char *listen_address = (char *)vim_tempname();
-    os_setenv(LISTEN_ADDRESS_ENV_VAR, listen_address, 1);
-    xfree(listen_address);
+  bool must_free = false;
+  const char *listen_address = os_getenv(LISTEN_ADDRESS_ENV_VAR);
+  if (listen_address == NULL || *listen_address == NUL) {
+    must_free = true;
+    listen_address = (char *)vim_tempname();
   }
 
-  return server_start((char *)os_getenv(LISTEN_ADDRESS_ENV_VAR)) == 0;
+  bool ok = (server_start(listen_address) == 0);
+  if (must_free) {
+    xfree((char *) listen_address);
+  }
+  return ok;
 }
 
-/// Teardown the server module
-void server_teardown(void)
+/// Retrieve the file handle from a server.
+static uv_handle_t *server_handle(Server *server)
 {
-  if (!servers) {
-    return;
-  }
+  return server->type == kServerTypeTcp
+    ? (uv_handle_t *)&server->socket.tcp.handle
+    : (uv_handle_t *) &server->socket.pipe.handle;
+}
 
-  Server *server;
+/// Teardown a single server
+static void server_close_cb(Server **server)
+{
+  uv_close(server_handle(*server), free_server);
+}
 
-  map_foreach_value(servers, server, {
-    if (server->type == kServerTypeTcp) {
-      uv_close((uv_handle_t *)&server->socket.tcp.handle, free_server);
-    } else {
-      uv_close((uv_handle_t *)&server->socket.pipe.handle, free_server);
-    }
-  });
+/// Teardown the server module
+void server_teardown(void)
+{
+  GA_DEEP_CLEAR(&servers, Server *, server_close_cb);
 }
 
 /// Starts listening on arbitrary tcp/unix addresses specified by
@@ -106,9 +115,11 @@ int server_start(const char *endpoint)
   }
 
   // Check if the server already exists
-  if (pmap_has(cstr_t)(servers, addr)) {
-    ELOG("Already listening on %s", addr);
-    return 1;
+  for (int i = 0; i < servers.ga_len; i++) {
+    if (strcmp(addr, ((Server **)servers.ga_data)[i]->addr) == 0) {
+      ELOG("Already listening on %s", addr);
+      return 1;
+    }
   }
 
   ServerType server_type = kServerTypeTcp;
@@ -154,6 +165,8 @@ int server_start(const char *endpoint)
   int result;
   uv_stream_t *stream = NULL;
 
+  xstrlcpy(server->addr, addr, sizeof(server->addr));
+
   if (server_type == kServerTypeTcp) {
     // Listen on tcp address/port
     uv_tcp_init(uv_default_loop(), &server->socket.tcp.handle);
@@ -163,10 +176,8 @@ int server_start(const char *endpoint)
     stream = (uv_stream_t *)&server->socket.tcp.handle;
   } else {
     // Listen on named pipe or unix socket
-    xstrlcpy(server->socket.pipe.addr, addr, sizeof(server->socket.pipe.addr));
     uv_pipe_init(uv_default_loop(), &server->socket.pipe.handle, 0);
-    result = uv_pipe_bind(&server->socket.pipe.handle,
-                          server->socket.pipe.addr);
+    result = uv_pipe_bind(&server->socket.pipe.handle, server->addr);
     stream = (uv_stream_t *)&server->socket.pipe.handle;
   }
 
@@ -193,9 +204,17 @@ int server_start(const char *endpoint)
     return result;
   }
 
+  // Update $NVIM_LISTEN_ADDRESS, if not set.
+  const char *listen_address = os_getenv(LISTEN_ADDRESS_ENV_VAR);
+  if (listen_address == NULL || *listen_address == NUL) {
+    os_setenv(LISTEN_ADDRESS_ENV_VAR, addr, 1);
+  }
+
   server->type = server_type;
-  // Add the server to the hash table
-  pmap_put(cstr_t)(servers, addr, server);
+
+  // Add the server to the list.
+  ga_grow(&servers, 1);
+  ((Server **)servers.ga_data)[servers.ga_len++] = server;
 
   return 0;
 }
@@ -211,18 +230,49 @@ void server_stop(char *endpoint)
   // Trim to `ADDRESS_MAX_SIZE`
   xstrlcpy(addr, endpoint, sizeof(addr));
 
-  if ((server = pmap_get(cstr_t)(servers, addr)) == NULL) {
+  int i = 0;  // The index of the server whose address equals addr.
+  for (; i < servers.ga_len; i++) {
+    server = ((Server **)servers.ga_data)[i];
+    if (strcmp(addr, server->addr) == 0) {
+      break;
+    }
+  }
+
+  if (i == servers.ga_len) {
     ELOG("Not listening on %s", addr);
     return;
   }
 
-  if (server->type == kServerTypeTcp) {
-    uv_close((uv_handle_t *)&server->socket.tcp.handle, free_server);
-  } else {
-    uv_close((uv_handle_t *)&server->socket.pipe.handle, free_server);
+  // If we are invalidating the listen address, unset it.
+  const char *listen_address = os_getenv(LISTEN_ADDRESS_ENV_VAR);
+  if (listen_address && strcmp(addr, listen_address) == 0) {
+    os_unsetenv(LISTEN_ADDRESS_ENV_VAR);
   }
 
-  pmap_del(cstr_t)(servers, addr);
+  uv_close(server_handle(server), free_server);
+
+  // Remove this server from the list by swapping it with the last item.
+  if (i != servers.ga_len - 1) {
+    ((Server **)servers.ga_data)[i] =
+      ((Server **)servers.ga_data)[servers.ga_len - 1];
+  }
+  servers.ga_len--;
+}
+
+/// Returns an allocated array of server addresses.
+/// @param[out] size The size of the returned array.
+char **server_address_list(size_t *size)
+  FUNC_ATTR_NONNULL_ALL
+{
+  if ((*size = (size_t) servers.ga_len) == 0) {
+    return NULL;
+  }
+
+  char **addrs = xcalloc((size_t) servers.ga_len, sizeof(const char **));
+  for (int i = 0; i < servers.ga_len; i++) {
+    addrs[i] = xstrdup(((Server **)servers.ga_data)[i]->addr);
+  }
+  return addrs;
 }
 
 static void connection_cb(uv_stream_t *server, int status)
diff --git a/src/nvim/os/env.c b/src/nvim/os/env.c
index 37158f4d3c..be4b22de3a 100644
--- a/src/nvim/os/env.c
+++ b/src/nvim/os/env.c
@@ -37,6 +37,19 @@ int os_setenv(const char *name, const char *value, int overwrite)
   return setenv(name, value, overwrite);
 }
 
+/// Unset environment variable
+///
+/// For systems where unsetenv() is not available the value will be set as an
+/// empty string
+int os_unsetenv(const char *name)
+{
+#ifdef HAVE_UNSETENV
+  return unsetenv(name);
+#else
+  return os_setenv(name, "", 1);
+#endif
+}
+
 char *os_getenvname_at_index(size_t index)
 {
 # if defined(HAVE__NSGETENVIRON)
diff --git a/test/functional/server/server_spec.lua b/test/functional/server/server_spec.lua
new file mode 100644
index 0000000000..5dd8197d52
--- /dev/null
+++ b/test/functional/server/server_spec.lua
@@ -0,0 +1,42 @@
+
+local helpers = require('test.functional.helpers')
+local nvim, eq, neq, ok, eval
+  = helpers.nvim, helpers.eq, helpers.neq, helpers.ok, helpers.eval
+local clear = helpers.clear
+
+describe('server*() functions', function()
+  before_each(clear)
+
+  it('set $NVIM_LISTEN_ADDRESS on first serverstart()', function()
+    -- Ensure the listen address is unset.
+    nvim('command', 'let $NVIM_LISTEN_ADDRESS = ""')
+    nvim('command', 'let s = serverstart()')
+    eq(1, eval('$NVIM_LISTEN_ADDRESS == s'))
+    nvim('command', 'call serverstop(s)')
+    eq(0, eval('$NVIM_LISTEN_ADDRESS == s'))
+  end)
+
+  it('let the user retrieve the list of servers', function()
+    -- There should already be at least one server.
+    local n = eval('len(serverlist())')
+
+    -- Add a few
+    local servs = {'should-not-exist', 'another-one-that-shouldnt'}
+    for _, s in ipairs(servs) do
+      eq(s, eval('serverstart("'..s..'")'))
+    end
+
+    local new_servs = eval('serverlist()')
+
+    -- Exactly #servs servers should be added.
+    eq(n + #servs, #new_servs)
+    -- The new servers should be at the end of the list.
+    for i = 1, #servs do
+      eq(servs[i], new_servs[i + n])
+      nvim('command', 'call serverstop("'..servs[i]..'")')
+    end
+    -- After calling serverstop() on the new servers, they should no longer be
+    -- in the list.
+    eq(n, eval('len(serverlist())'))
+  end)
+end)
diff --git a/test/unit/os/env_spec.lua b/test/unit/os/env_spec.lua
index 5896f5ddd4..9d936c2564 100644
--- a/test/unit/os/env_spec.lua
+++ b/test/unit/os/env_spec.lua
@@ -3,6 +3,7 @@ local helpers = require('test.unit.helpers')
 local cimport = helpers.cimport
 local internalize = helpers.internalize
 local eq = helpers.eq
+local neq = helpers.neq
 local ffi = helpers.ffi
 local lib = helpers.lib
 local cstr = helpers.cstr
@@ -21,6 +22,10 @@ describe('env function', function()
     return env.os_setenv((to_cstr(name)), (to_cstr(value)), override)
   end
 
+  function os_unsetenv(name, value, override)
+    return env.os_unsetenv((to_cstr(name)))
+  end
+
   function os_getenv(name)
     local rval = env.os_getenv((to_cstr(name)))
     if rval ~= NULL then
@@ -68,6 +73,18 @@ describe('env function', function()
     end)
   end)
 
+  describe('os_unsetenv', function()
+    it('unsets environment variable', function()
+      local name = 'TEST_UNSETENV'
+      local value = 'TESTVALUE'
+      os_setenv(name, value, 1)
+      os_unsetenv(name)
+      neq(os_getenv(name), value)
+      -- Depending on the platform the var might be unset or set as ''
+      assert.True(os_getenv(name) == nil or os_getenv(name) == '')
+    end)
+  end)
+
   describe('os_getenvname_at_index', function()
     it('returns names of environment variables', function()
       local test_name = 'NEOVIM_UNIT_TEST_GETENVNAME_AT_INDEX_1N'