ui: vm preview

Terminal must support kitty graphics protocol.
New config parameters:

[preview]
enabled = 0|1
scale = 0|1
png_path = /path/to/vm.png

Author: 0x501D

CHANGES

@@ -1,5 +1,14 @@
 unreleased
 ------------------------
+    - Feature: VM preview
+        Terminal must support kitty graphics protocol
+        New config parameters:
+          [preview]
+          enabled = 0|1
+          scale = 0|1
+          png_path = /path/to/vm.png
+    - Feature: configurable refresh timeout for properties window
+        Parameter `refresh_timeout` in `main` section
     - Feature: image format type support: qcow2 and raw
     - Bugfix: fix import on some locales
 

nemu.cfg.sample

@@ -25,6 +25,14 @@ db = /home/user/.nemu.db
 # if not set VTE's default cursor style will be used
 # cursor_style = 1
 
+# Properties refresh timeout (ms)
+# refresh_timeout = 500
+
+[preview]
+# enabled = 0
+# scale = 0
+# png_path = /tmp/nemu.png
+
 [viewer]
 # default protocol (1 - spice, 0 - vnc)
 spice_default = 1

src/nm_cfg_file.c

@@ -31,17 +31,21 @@ static const char NM_DEFAULT_SPICE[]    = "/usr/bin/remote-viewer";
 static const char NM_DEFAULT_QEMUDIR[]  = "/usr/bin";
 #endif /* NM_WITH_QEMU */
 
+static const int NM_DEFAULT_REFRESH = 500;
+
 static const char NM_DEFAULT_VNCARG[]   = ":%p";
 static const char NM_DEFAULT_SPICEARG[] = "--title %t spice://127.0.0.1:%p";
 
 static const char NM_DEFAULT_TARGET[]   = "x86_64,i386";
 
 static const char NM_DEFAULT_PID[]      = "/tmp/nemu.pid";
+static const char NM_DEFAULT_PNG[]      = "/tmp/nemu.png";
 
 static const char NM_INI_S_MAIN[]       = "main";
 static const char NM_INI_S_VIEW[]       = "viewer";
 static const char NM_INI_S_QEMU[]       = "qemu";
 static const char NM_INI_S_DMON[]       = "nemu-monitor";
+static const char NM_INI_S_PREV[]       = "preview";
 
 static const char NM_INI_P_VM[]         = "vmdir";
 static const char NM_INI_P_DB[]         = "db";
@@ -64,6 +68,7 @@ static const char NM_INI_P_AUTO[]       = "autostart";
 static const char NM_INI_P_SLP[]        = "sleep";
 static const char NM_INI_P_GL_SEP[]     = "glyph_separator";
 static const char NM_INI_P_GL_CHECK[]   = "glyph_checkbox";
+static const char NM_INI_P_REFRESH[]    = "refresh_timeout";
 #if defined (NM_WITH_REMOTE)
 static const char NM_INI_P_API_SRV[]    = "remote_control";
 static const char NM_INI_P_API_IFACE[]  = "remote_interface";
@@ -77,6 +82,9 @@ static const char NM_INI_P_API_HASH[]   = "remote_hash";
 static const char NM_INI_P_DYES[]       = "dbus_enabled";
 static const char NM_INI_P_DTMT[]       = "dbus_timeout";
 #endif
+static const char NM_INI_P_PREV_FLAG[]  = "enabled";
+static const char NM_INI_P_PREV_SCALE[] = "scale";
+static const char NM_INI_P_PREV_PATH[]  = "png_path";
 
 static const char * const CURSOR_STYLE_STR[]   = {
     "Default",
@@ -355,6 +363,34 @@ void nm_cfg_init(bool bypass_cfg)
         cfg.glyphs.checkbox = !!nm_str_stoui(&tmp_buf, 10);
     }
 
+    nm_str_trunc(&tmp_buf, 0);
+    if (nm_get_opt_param(ini, NM_INI_S_MAIN, NM_INI_P_REFRESH,
+                &tmp_buf) == NM_OK) {
+        cfg.refresh_timeout = nm_str_stoul(&tmp_buf, 10);
+    } else {
+        cfg.refresh_timeout = NM_DEFAULT_REFRESH;
+    }
+
+    /* VM preview */
+    nm_str_trunc(&tmp_buf, 0);
+    if (nm_get_opt_param(ini, NM_INI_S_PREV, NM_INI_P_PREV_FLAG,
+                &tmp_buf) == NM_OK) {
+        cfg.preview.enabled = !!nm_str_stoui(&tmp_buf, 10);
+    } else {
+        cfg.preview.enabled = 0;
+    }
+    nm_str_trunc(&tmp_buf, 0);
+    if (nm_get_opt_param(ini, NM_INI_S_PREV, NM_INI_P_PREV_SCALE,
+                &tmp_buf) == NM_OK) {
+        cfg.preview.scale = !!nm_str_stoui(&tmp_buf, 10);
+    } else {
+        cfg.preview.scale = 0;
+    }
+    if (nm_get_opt_param(ini, NM_INI_S_PREV, NM_INI_P_PREV_PATH,
+                &cfg.preview.path) != NM_OK) {
+        nm_str_alloc_text(&cfg.preview.path, NM_DEFAULT_PNG);
+    }
+
 #if defined (NM_WITH_REMOTE)
     nm_str_trunc(&tmp_buf, 0);
     cfg.api_server = 0;
@@ -428,6 +464,7 @@ void nm_cfg_free(void)
     nm_str_free(&cfg.pid);
     nm_str_free(&cfg.daemon_pid);
     nm_str_free(&cfg.qemu_bin_path);
+    nm_str_free(&cfg.preview.path);
     nm_vect_free(&cfg.qemu_targets, NULL);
 #if defined (NM_WITH_REMOTE)
     nm_str_free(&cfg.api_cert_path);
@@ -605,6 +642,11 @@ static void nm_generate_cfg(const char *home, const nm_str_t *cfg_path)
                     "# see https://terminalguide.namepad.de/seq/csi_sq_t_space/"
                     "\n# if not set VTE's default cursor style will be used\n"
                     "# cursor_style = 1\n\n");
+            fprintf(cfg_file, "# Properties refresh timeout (ms)\n"
+                    "# refresh_timeout = 500\n\n");
+            fprintf(cfg_file, "[preview]\n");
+            fprintf(cfg_file, "# enabled = 0\n# scale = 0\n"
+                    "# png_path = /tmp/nemu.png\n\n");
             fprintf(cfg_file, "[viewer]\n");
             fprintf(cfg_file, "# default protocol (1 - spice, 0 - vnc)"
                     "\nspice_default = 1\n\n");

src/nm_cfg_file.h

@@ -26,6 +26,12 @@ typedef struct {
     uint32_t checkbox:1;
 } nm_glyph_t;
 
+typedef struct {
+    nm_str_t path;
+    uint32_t enabled:1;
+    uint32_t scale:1;
+} nm_preview_t;
+
 typedef struct {
     nm_str_t vm_dir;
     nm_str_t db_path;
@@ -43,8 +49,10 @@ typedef struct {
     nm_rgb_t hl_color;
     nm_rgb_t err_color;
     nm_glyph_t glyphs;
+    nm_preview_t preview;
     nm_str_t debug_path;
     uint64_t daemon_sleep;
+    uint64_t refresh_timeout;
     uint32_t cursor_style;
 #if defined (NM_WITH_DBUS)
     uint32_t dbus_enabled:1;

src/nm_main_loop.c

@@ -188,6 +188,10 @@ void nm_start_main_loop(void)
          * Otherwise text will be flicker in tty.
          */
         if (ch != ERR) {
+            if (cfg->preview.enabled) {
+                printf("\x1b_Ga=d,d=i,i=20509,q=2;\x1b\x5c");
+                fflush(stdout);
+            }
             clear_action = 1;
         }
 

src/nm_qmp_control.c

@@ -84,6 +84,10 @@ static const char NM_QMP_DEV_NET_ADD[] =
 static const char NM_QMP_DEV_DEL[] =
     "{'execute':'device_del','arguments':{'id':'dev-%s'}}";
 
+static const char NM_QMP_TAKE_SCREENSHOT[] =
+    "{'execute':'screendump','arguments':{'filename':'%s',"
+    "'format':'png'}}";
+
 #if defined NM_OS_LINUX
 static const char NM_QMP_NET_TAP_FD_ADD[] =
     "{'execute':'netdev_add','arguments':{'type':'tap',"
@@ -152,6 +156,16 @@ void nm_qmp_vm_resume(const nm_str_t *name)
     nm_qmp_vm_exec(name, NM_QMP_CMD_VM_CONT, &tv);
 }
 
+void nm_qmp_take_screenshot(const nm_str_t *name, const nm_str_t *path)
+{
+    nm_str_t qmp_query = NM_INIT_STR;
+    struct timeval tv = { .tv_sec = 0, .tv_usec = 1000000 }; /* 1s */
+
+    nm_str_format(&qmp_query, NM_QMP_TAKE_SCREENSHOT, path->data);
+    nm_qmp_vm_exec(name, qmp_query.data, &tv);
+    nm_str_free(&qmp_query);
+}
+
 int nm_qmp_savevm(const nm_str_t *name, const nm_str_t *snap)
 {
     nm_vect_t drives = NM_INIT_VECT;

src/nm_qmp_control.h

@@ -10,6 +10,7 @@ void nm_qmp_vm_stop(const nm_str_t *name);
 void nm_qmp_vm_reset(const nm_str_t *name);
 void nm_qmp_vm_pause(const nm_str_t *name);
 void nm_qmp_vm_resume(const nm_str_t *name);
+void nm_qmp_take_screenshot(const nm_str_t *name, const nm_str_t *path);
 int nm_qmp_savevm(const nm_str_t *name, const nm_str_t *snap);
 int nm_qmp_loadvm(const nm_str_t *name, const nm_str_t *snap);
 int nm_qmp_delvm(const nm_str_t *name, const nm_str_t *snap);

src/nm_utils.c

@@ -587,4 +587,44 @@ nm_get_drive_size(const nm_str_t *path, off_t *virtual_size, off_t *actual_size)
     nm_vect_free(&cmdv, NULL);
     json_object_put(js);
 }
+
+static const char
+b64_chars[] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+char *nm_64_encode(const uint8_t *src, size_t src_len)
+{
+    size_t res_len;
+    char *res;
+
+    res_len = 4 * ((src_len + 2) / 3);
+    res = nm_calloc(1, res_len + 1);
+    if (!res) {
+        return NULL;
+    }
+
+    for (size_t i = 0, j = 0; i < src_len; i += 3, j += 4) {
+        size_t a = i < src_len ? src[i] : 0;
+        size_t b = i + 1 < src_len ? src[i + 1] : 0;
+        size_t c = i + 2 < src_len ? src[i + 2] : 0;
+        size_t abc = (a << 0x10) + (b << 0x8) + c;
+
+        res[j] = b64_chars[(abc >> 18) & 0x3F];
+        res[j + 1] = b64_chars[(abc >> 12) & 0x3F];
+
+        if (i + 1 < src_len) {
+            res[j + 2] = b64_chars[(abc >> 6) & 0x3F];
+        } else {
+            res[j + 2] = '=';
+        }
+
+        if (i + 2 < src_len) {
+            res[j + 3] = b64_chars[abc & 0x3F];
+        } else {
+            res[j + 3] = '=';
+        }
+    }
+
+    return res;
+}
 /* vim:set ts=4 sw=4: */

src/nm_utils.h

@@ -66,5 +66,8 @@ void nm_get_time(nm_str_t *res, const char *fmt);
 void nm_gen_rand_str(nm_str_t *res, size_t len);
 void nm_gen_uid(nm_str_t *res);
 
+/* Caller must free the return value. */
+char *nm_64_encode(const uint8_t *src, size_t src_len);
+
 #endif /* NM_UTILS_H_ */
 /* vim:set ts=4 sw=4: */

src/nm_window.c

@@ -8,6 +8,7 @@
 #include <nm_cfg_file.h>
 #include <nm_usb_plug.h>
 #include <nm_stat_usage.h>
+#include <nm_qmp_control.h>
 
 static float nm_window_scale = 0.7;
 
@@ -140,7 +141,7 @@ void nm_init_side(void)
         nm_init_window__(side_window, _("VM list"));
     }
 
-    wtimeout(side_window, 500);
+    wtimeout(side_window, nm_cfg_get()->refresh_timeout);
 }
 
 void nm_init_side_lan(void)
@@ -629,7 +630,7 @@ nm_print_vm_info(const nm_str_t *name, const nm_vmctl_data_t *vm, int status)
 
     }
 
-    /* print PID */
+    /* print runtime statistics and screen preview if enabled */
     {
         int fd;
         nm_str_t pid_path = NM_INIT_STR;
@@ -662,12 +663,45 @@ nm_print_vm_info(const nm_str_t *name, const nm_vmctl_data_t *vm, int status)
 #else
             (void) pid_num;
 #endif
+            if (nm_cfg_get()->preview.enabled) {
+                char *b64;
+                nm_file_map_t png = NM_INIT_FILE;
+                size_t side_cols, NM_UNUSED side_rows;
+
+                nm_qmp_take_screenshot(name, &nm_cfg_get()->preview.path);
+                png.name = &nm_cfg_get()->preview.path;
+                nm_map_file(&png);
+                b64 = nm_64_encode(png.mp, png.size);
+
+                getmaxyx(side_window, side_rows, side_cols);
+
+                if (nm_cfg_get()->preview.scale) {
+                    nm_str_format(&buf,
+                            "\x1b_Gi=20509,q=2,a=T,C=1,c=%zu,r=%zu,f=100;%s"
+                            "\x1b\x5c",
+                            cols - 4, rows - y - 2, b64);
+                } else {
+                    nm_str_format(&buf,
+                            "\x1b_Gi=20509,q=2,a=T,C=1,r=%zu,f=100;%s\x1b\x5c",
+                            rows - y - 3, b64);
+                }
+                mvcur(42, 42, y + 2, side_cols + 2);
+                printf("%s", buf.data);
+                fflush(stdout);
+
+                nm_unmap_file(&png);
+                free(b64);
+            }
         } else { /* clear PID file info and cpu usage data */
             if (y < (rows - 2)) {
                 mvwhline(action_window, y, 1, ' ', cols - 4);
                 mvwhline(action_window, y + 1, 1, ' ', cols - 4);
             }
             NM_STAT_CLEAN();
+            if (nm_cfg_get()->preview.enabled) {
+                printf("\x1b_Ga=d,d=i,i=20509,q=2;\x1b\x5c");
+                fflush(stdout);
+            }
         }
 
         nm_str_free(&pid_path);