libnbd/0002-info-Add-limited-colourized-output.patch

From bf4a8911c992291e6943d5e936732c290ea2abb9 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Tue, 2 Aug 2022 10:38:56 +0100
Subject: [PATCH 2/3] info: Add limited colourized output

For terminal, non-JSON output, colourize some of the output.  We can
work on making this better later.  Use --no-colour (or output to a
non-terminal) to disable colours.
---
 info/main.c      | 25 ++++++++++++-
 info/map.c       | 95 ++++++++++++++++++++++++++++++++++++++----------
 info/nbdinfo.pod | 11 ++++++
 info/show.c      | 38 ++++++++++++++-----
 4 files changed, 138 insertions(+), 31 deletions(-)

diff --git a/info/main.c b/info/main.c
index 870abb4623..a4550e2294 100644
--- a/info/main.c
+++ b/info/main.c
@@ -1,5 +1,5 @@
 /* NBD client library in userspace
- * Copyright (C) 2020-2021 Red Hat Inc.
+ * Copyright (C) 2020-2022 Red Hat Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -30,6 +30,7 @@
 
 #include <libnbd.h>
 
+#include "ansi-colours.h"
 #include "version.h"
 
 #include "nbdinfo.h"
@@ -37,6 +38,7 @@
 const char *progname;
 struct nbd_handle *nbd;
 FILE *fp;                       /* output file descriptor */
+bool colour;                    /* --colour / --no-colour option */
 bool list_all = false;          /* --list option */
 bool probe_content = false;     /* --content / --no-content option */
 bool json_output = false;       /* --json option */
@@ -93,6 +95,8 @@ main (int argc, char *argv[])
     HELP_OPTION = CHAR_MAX + 1,
     LONG_OPTIONS,
     SHORT_OPTIONS,
+    COLOUR_OPTION,
+    NO_COLOUR_OPTION,
     CONTENT_OPTION,
     NO_CONTENT_OPTION,
     JSON_OPTION,
@@ -105,6 +109,14 @@ main (int argc, char *argv[])
   const struct option long_options[] = {
     { "help",               no_argument,       NULL, HELP_OPTION },
     { "can",                required_argument, NULL, CAN_OPTION },
+    { "color",              no_argument,       NULL, COLOUR_OPTION },
+    { "colors",             no_argument,       NULL, COLOUR_OPTION },
+    { "colour",             no_argument,       NULL, COLOUR_OPTION },
+    { "colours",            no_argument,       NULL, COLOUR_OPTION },
+    { "no-color",           no_argument,       NULL, NO_COLOUR_OPTION },
+    { "no-colors",          no_argument,       NULL, NO_COLOUR_OPTION },
+    { "no-colour",          no_argument,       NULL, NO_COLOUR_OPTION },
+    { "no-colours",         no_argument,       NULL, NO_COLOUR_OPTION },
     { "content",            no_argument,       NULL, CONTENT_OPTION },
     { "no-content",         no_argument,       NULL, NO_CONTENT_OPTION },
     { "is",                 required_argument, NULL, CAN_OPTION },
@@ -127,6 +139,7 @@ main (int argc, char *argv[])
   bool list_okay = true;
 
   progname = argv[0];
+  colour = isatty (STDOUT_FILENO);
 
   for (;;) {
     c = getopt_long (argc, argv, short_options, long_options, NULL);
@@ -156,6 +169,14 @@ main (int argc, char *argv[])
       json_output = true;
       break;
 
+    case COLOUR_OPTION:
+      colour = true;
+      break;
+
+    case NO_COLOUR_OPTION:
+      colour = false;
+      break;
+
     case CONTENT_OPTION:
       content_flag = true;
       break;
@@ -288,10 +309,12 @@ main (int argc, char *argv[])
 
     if (!json_output) {
       if (protocol) {
+        ansi_colour (ANSI_FG_MAGENTA, fp);
         fprintf (fp, "protocol: %s", protocol);
         if (tls_negotiated >= 0)
           fprintf (fp, " %s TLS", tls_negotiated ? "with" : "without");
         fprintf (fp, "\n");
+        ansi_restore (fp);
       }
     }
     else {
diff --git a/info/map.c b/info/map.c
index 39c5933bf5..a5aad95522 100644
--- a/info/map.c
+++ b/info/map.c
@@ -30,6 +30,7 @@
 
 #include <libnbd.h>
 
+#include "ansi-colours.h"
 #include "minmax.h"
 #include "vector.h"
 
@@ -99,7 +100,9 @@ do_map (void)
 
 /* Callback handling --map. */
 static void print_one_extent (uint64_t offset, uint64_t len, uint32_t type);
-static char *extent_description (const char *metacontext, uint32_t type);
+static void extent_description (const char *metacontext, uint32_t type,
+                                char **descr, bool *free_descr,
+                                const char **fg, const char **bg);
 
 static int
 extent_callback (void *user_data, const char *metacontext,
@@ -169,15 +172,25 @@ static void
 print_one_extent (uint64_t offset, uint64_t len, uint32_t type)
 {
   static bool comma = false;
-  char *descr = extent_description (map, type);
+  char *descr;
+  bool free_descr;
+  const char *fg, *bg;
+
+  extent_description (map, type, &descr, &free_descr, &fg, &bg);
 
   if (!json_output) {
+    if (fg)
+      ansi_colour (fg, fp);
+    if (bg)
+      ansi_colour (bg, fp);
     fprintf (fp, "%10" PRIu64 "  "
              "%10" PRIu64 "  "
              "%3" PRIu32,
              offset, len, type);
     if (descr)
       fprintf (fp, "  %s", descr);
+    if (fg || bg)
+      ansi_restore (fp);
     fprintf (fp, "\n");
   }
   else {
@@ -196,7 +209,8 @@ print_one_extent (uint64_t offset, uint64_t len, uint32_t type)
     comma = true;
   }
 
-  free (descr);
+  if (free_descr)
+    free (descr);
 }
 
 /* --map --totals suboption */
@@ -237,14 +251,24 @@ print_totals (uint32_vector *entries, int64_t size)
     }
 
     if (c > 0) {
-      char *descr = extent_description (map, type);
+      char *descr;
+      bool free_descr;
+      const char *fg, *bg;
       double percent = 100.0 * c / size;
 
+      extent_description (map, type, &descr, &free_descr, &fg, &bg);
+
       if (!json_output) {
+        if (fg)
+          ansi_colour (fg, fp);
+        if (bg)
+          ansi_colour (bg, fp);
         fprintf (fp, "%10" PRIu64 " %5.1f%% %3" PRIu32,
                  c, percent, type);
         if (descr)
           fprintf (fp, " %s", descr);
+        if (fg || bg)
+          ansi_restore (fp);
         fprintf (fp, "\n");
       }
       else {
@@ -264,7 +288,8 @@ print_totals (uint32_vector *entries, int64_t size)
         comma = true;
       }
 
-      free (descr);
+      if (free_descr)
+        free (descr);
     }
 
     if (next_type == (uint64_t)UINT32_MAX + 1)
@@ -275,37 +300,67 @@ print_totals (uint32_vector *entries, int64_t size)
   if (json_output) fprintf (fp, "\n]\n");
 }
 
-static char *
-extent_description (const char *metacontext, uint32_t type)
+static void
+extent_description (const char *metacontext, uint32_t type,
+                    char **descr, bool *free_descr,
+                    const char **fg, const char **bg)
 {
-  char *ret;
-
   if (strcmp (metacontext, "base:allocation") == 0) {
     switch (type) {
-    case 0: return strdup ("data");
-    case 1: return strdup ("hole");
-    case 2: return strdup ("zero");
-    case 3: return strdup ("hole,zero");
+    case 0:
+      *descr = "data"; *free_descr = false;
+      *fg = ANSI_FG_BOLD_BLACK; *bg = NULL;
+      return;
+    case 1:
+      *descr = "hole"; *free_descr = false;
+      *fg = *bg = NULL;
+      return;
+    case 2:
+      *descr = "zero"; *free_descr = false;
+      *fg = *bg = NULL;
+      return;
+    case 3:
+      *descr = "hole,zero"; *free_descr = false;
+      *fg = *bg = NULL;
+      return;
     }
   }
   else if (strncmp (metacontext, "qemu:dirty-bitmap:", 18) == 0) {
     switch (type) {
-    case 0: return strdup ("clean");
-    case 1: return strdup ("dirty");
+    case 0:
+      *descr = "clean"; *free_descr = false;
+      *fg = ANSI_FG_GREEN; *bg = NULL;
+      return;
+    case 1:
+      *descr = "dirty"; *free_descr = false;
+      *fg = ANSI_FG_RED; *bg = NULL;
+      return;
     }
   }
   else if (strcmp (metacontext, "qemu:allocation-depth") == 0) {
     switch (type) {
-    case 0: return strdup ("absent");
-    case 1: return strdup ("local");
+    case 0:
+      *descr = "absent"; *free_descr = false;
+      *fg = *bg = NULL;
+      return;
+    case 1:
+      *descr = "local"; *free_descr = false;
+      *fg = ANSI_FG_BRIGHT_WHITE; *bg = ANSI_BG_BLACK;
+      return;
     default:
-      if (asprintf (&ret, "backing depth %u", type) == -1) {
+      if (asprintf (descr, "backing depth %u", type) == -1) {
         perror ("asprintf");
         exit (EXIT_FAILURE);
       }
-      return ret;
+      *free_descr = true;
+      *fg = NULL; *bg = ANSI_BG_LIGHT_GREY;
+      return;
     }
   }
 
-  return NULL;   /* Don't know - description field will be omitted. */
+  /* Don't know - description field will be omitted. */
+  *descr = NULL;
+  *free_descr = false;
+  *fg = NULL;
+  *bg = NULL;
 }
diff --git a/info/nbdinfo.pod b/info/nbdinfo.pod
index 4733ecd1f7..7dfb9edb60 100644
--- a/info/nbdinfo.pod
+++ b/info/nbdinfo.pod
@@ -330,6 +330,17 @@ L<nbd_can_df(3)>, L<nbd_can_fast_zero(3)>, L<nbd_can_flush(3)>,
 L<nbd_can_fua(3)>, L<nbd_can_multi_conn(3)>, L<nbd_can_trim(3)>,
 L<nbd_can_zero(3)>, L<nbd_is_read_only(3)>.
 
+=item B<--color>
+
+=item B<--colour>
+
+=item B<--no-color>
+
+=item B<--no-colour>
+
+Enable or disable ANSI colours in output.  By default we use colours
+if the output seems to be a terminal, and disable them if not.
+
 =item B<--content>
 
 =item B<--no-content>
diff --git a/info/show.c b/info/show.c
index 3a436665bf..140220d8c6 100644
--- a/info/show.c
+++ b/info/show.c
@@ -28,11 +28,13 @@
 
 #include <libnbd.h>
 
+#include "ansi-colours.h"
 #include "human-size.h"
 #include "string-vector.h"
 
 #include "nbdinfo.h"
 
+static void show_boolean (const char *name, bool cond);
 static int collect_context (void *opaque, const char *name);
 static char *get_content (struct nbd_handle *, int64_t size);
 
@@ -119,6 +121,7 @@ show_one_export (struct nbd_handle *nbd, const char *desc,
   content = get_content (nbd, size);
 
   if (!json_output) {
+    ansi_colour (ANSI_FG_BRIGHT_BLUE, fp);
     fprintf (fp, "export=");
     /* Might as well use the JSON function to get an escaped string here ... */
     print_json_string (export_name);
@@ -133,35 +136,38 @@ show_one_export (struct nbd_handle *nbd, const char *desc,
       fprintf (fp, "\tcontent: %s\n", content);
     if (uri)
       fprintf (fp, "\turi: %s\n", uri);
+    ansi_restore (fp);
+    ansi_colour (ANSI_FG_BLUE, fp);
     if (show_context) {
       fprintf (fp, "\tcontexts:\n");
       for (i = 0; i < contexts.len; ++i)
         fprintf (fp, "\t\t%s\n", contexts.ptr[i]);
     }
+    ansi_restore (fp);
+    ansi_colour (ANSI_FG_MAGENTA, fp);
     if (is_rotational >= 0)
       fprintf (fp, "\t%s: %s\n", "is_rotational",
                is_rotational ? "true" : "false");
     if (is_read_only >= 0)
       fprintf (fp, "\t%s: %s\n", "is_read_only",
                is_read_only ? "true" : "false");
+    ansi_restore (fp);
     if (can_cache >= 0)
-      fprintf (fp, "\t%s: %s\n", "can_cache", can_cache ? "true" : "false");
+      show_boolean ("can_cache", can_cache);
     if (can_df >= 0)
-      fprintf (fp, "\t%s: %s\n", "can_df", can_df ? "true" : "false");
+      show_boolean ("can_df", can_df);
     if (can_fast_zero >= 0)
-      fprintf (fp, "\t%s: %s\n", "can_fast_zero",
-               can_fast_zero ? "true" : "false");
+      show_boolean ("can_fast_zero", can_fast_zero);
     if (can_flush >= 0)
-      fprintf (fp, "\t%s: %s\n", "can_flush", can_flush ? "true" : "false");
+      show_boolean ("can_flush", can_flush);
     if (can_fua >= 0)
-      fprintf (fp, "\t%s: %s\n", "can_fua", can_fua ? "true" : "false");
+      show_boolean ("can_fua", can_fua);
     if (can_multi_conn >= 0)
-      fprintf (fp, "\t%s: %s\n", "can_multi_conn",
-               can_multi_conn ? "true" : "false");
+      show_boolean ("can_multi_conn", can_multi_conn);
     if (can_trim >= 0)
-      fprintf (fp, "\t%s: %s\n", "can_trim", can_trim ? "true" : "false");
+      show_boolean ("can_trim", can_trim);
     if (can_zero >= 0)
-      fprintf (fp, "\t%s: %s\n", "can_zero", can_zero ? "true" : "false");
+      show_boolean ("can_zero", can_zero);
     if (block_minimum > 0)
       fprintf (fp, "\t%s: %" PRId64 "\n", "block_size_minimum", block_minimum);
     if (block_preferred > 0)
@@ -269,6 +275,18 @@ show_one_export (struct nbd_handle *nbd, const char *desc,
   return true;
 }
 
+/* Used for displaying booleans in non-JSON output. */
+static void
+show_boolean (const char *name, bool cond)
+{
+  if (cond)
+    ansi_colour (ANSI_FG_GREEN, fp);
+  else
+    ansi_colour (ANSI_FG_RED, fp);
+  fprintf (fp, "\t%s: %s\n", name, cond ? "true" : "false");
+  ansi_restore (fp);
+}
+
 static int
 collect_context (void *opaque, const char *name)
 {
-- 
2.37.0.rc2