[libglnx] Import console from rpm-ostree

[Colin Walters <walters src gnome org>]

commit 64936b67001410974f1bd92803a46cdb77f89db5
Author: Colin Walters <walters verbum org>
Date:   Sun Feb 15 18:18:54 2015 -0500

    Import console from rpm-ostree
    
    This contains some basic progress bar drawing code for now.

 Makefile-libglnx.am |    2 +
 glnx-console.c      |  268 +++++++++++++++++++++++++++++++++++++++++++++++++++
 glnx-console.h      |   47 +++++++++
 libglnx.h           |    1 +
 4 files changed, 318 insertions(+), 0 deletions(-)
---
diff --git a/Makefile-libglnx.am b/Makefile-libglnx.am
index a04f19e..7463395 100644
--- a/Makefile-libglnx.am
+++ b/Makefile-libglnx.am
@@ -24,6 +24,8 @@ libglnx_la_SOURCES = \
        $(libglnx_srcpath)/glnx-local-alloc.c \
        $(libglnx_srcpath)/glnx-errors.h \
        $(libglnx_srcpath)/glnx-errors.c \
+       $(libglnx_srcpath)/glnx-console.h \
+       $(libglnx_srcpath)/glnx-console.c \
        $(libglnx_srcpath)/glnx-dirfd.h \
        $(libglnx_srcpath)/glnx-dirfd.c \
        $(libglnx_srcpath)/glnx-xattrs.h \
diff --git a/glnx-console.c b/glnx-console.c
new file mode 100644
index 0000000..5ae29b1
--- /dev/null
+++ b/glnx-console.c
@@ -0,0 +1,268 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2013,2014,2015 Colin Walters <walters verbum org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2 of the licence or (at
+ * your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include "glnx-console.h"
+
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+
+static char *current_text = NULL;
+static gint current_percent = -1;
+static gboolean locked;
+
+static gboolean
+stdout_is_tty (void)
+{
+  static gsize initialized = 0;
+  static gboolean stdout_is_tty_v;
+
+  if (g_once_init_enter (&initialized))
+    {
+      stdout_is_tty_v = isatty (1);
+      g_once_init_leave (&initialized, 1);
+    }
+
+  return stdout_is_tty_v;
+}
+
+static volatile guint cached_columns = 0;
+static volatile guint cached_lines = 0;
+
+static int
+fd_columns (int fd)
+{
+  struct winsize ws = {};
+
+  if (ioctl (fd, TIOCGWINSZ, &ws) < 0)
+    return -errno;
+
+  if (ws.ws_col <= 0)
+    return -EIO;
+
+  return ws.ws_col;
+}
+
+static guint
+columns (void)
+{
+  if (G_UNLIKELY (cached_columns == 0))
+    {
+      int c;
+
+      c = fd_columns (STDOUT_FILENO);
+
+      if (c <= 0)
+        c = 80;
+
+      if (c > 256)
+        c = 256;
+
+      cached_columns = c;
+    }
+
+  return cached_columns;
+}
+
+#if 0
+static int
+fd_lines (int fd)
+{
+  struct winsize ws = {};
+
+  if (ioctl (fd, TIOCGWINSZ, &ws) < 0)
+    return -errno;
+
+  if (ws.ws_row <= 0)
+    return -EIO;
+
+  return ws.ws_row;
+}
+
+static guint
+lines (void)
+{
+  if (G_UNLIKELY (cached_lines == 0))
+    {
+      int l;
+
+      l = fd_lines (STDOUT_FILENO);
+
+      if (l <= 0)
+        l = 24;
+
+      cached_lines = l;
+    }
+
+  return cached_lines;
+}
+#endif
+
+static void
+on_sigwinch (int signum)
+{
+  cached_columns = 0;
+  cached_lines = 0;
+}
+
+void
+glnx_console_lock (GLnxConsoleRef *console)
+{
+  static gsize sigwinch_initialized = 0;
+
+  if (!stdout_is_tty ())
+    return;
+
+  g_return_if_fail (!locked);
+  g_return_if_fail (!console->locked);
+
+  locked = console->locked = TRUE;
+
+  current_percent = 0;
+
+  if (g_once_init_enter (&sigwinch_initialized))
+    {
+      signal (SIGWINCH, on_sigwinch);
+      g_once_init_leave (&sigwinch_initialized, 1);
+    }
+
+  { static const char initbuf[] = { '\n', 0x1B, 0x37 };
+    (void) fwrite (initbuf, 1, sizeof (initbuf), stdout);
+  }
+}
+
+static void
+printpad (const char *padbuf,
+          guint       padbuf_len,
+          guint       n)
+{
+  const guint d = n / padbuf_len;
+  const guint r = n % padbuf_len;
+  guint i;
+
+  for (i = 0; i < d; i++)
+    fwrite (padbuf, 1, padbuf_len, stdout);
+  fwrite (padbuf, 1, r, stdout);
+}
+
+/**
+ * glnx_console_progress_text_percent:
+ * @text: Show this text before the progress bar
+ * @percentage: An integer in the range of 0 to 100
+ *
+ * Print to the console @text followed by an ASCII art progress bar
+ * whose percentage is @percentage.
+ *
+ * You must have called glnx_console_lock() before invoking this
+ * function.
+ *
+ * Currently, if stdout is not a tty, this function does nothing.
+ */
+void
+glnx_console_progress_text_percent (const char *text,
+                                    guint percentage)
+{
+  static const char equals[] = "====================";
+  const guint n_equals = sizeof (equals) - 1;
+  static const char spaces[] = "                    ";
+  const guint n_spaces = sizeof (spaces) - 1;
+  const guint ncolumns = columns ();
+  const guint bar_min = 10;
+  const guint input_textlen = text ? strlen (text) : 0;
+  guint textlen;
+  guint barlen;
+
+  if (!stdout_is_tty ())
+    return;
+
+  g_return_if_fail (percentage >= 0 && percentage <= 100);
+
+  if (text && !*text)
+    text = NULL;
+
+  if (percentage == current_percent
+      && g_strcmp0 (text, current_text) == 0)
+    return;
+
+  if (ncolumns < bar_min)
+    return; /* TODO: spinner */
+
+  /* Restore cursor */
+  { const char beginbuf[2] = { 0x1B, 0x38 };
+    (void) fwrite (beginbuf, 1, sizeof (beginbuf), stdout);
+  }
+
+  textlen = MIN (input_textlen, ncolumns - bar_min);
+  barlen = ncolumns - textlen;
+
+  if (textlen > 0)
+    {
+      fwrite (text, 1, textlen - 1, stdout);
+      fputc (' ', stdout);
+    }
+  
+  { 
+    const guint nbraces = 2;
+    const guint textpercent_len = 5;
+    const guint bar_internal_len = barlen - nbraces - textpercent_len;
+    const guint eqlen = bar_internal_len * (percentage / 100.0);
+    const guint spacelen = bar_internal_len - eqlen; 
+
+    fputc ('[', stdout);
+    printpad (equals, n_equals, eqlen);
+    printpad (spaces, n_spaces, spacelen);
+    fputc (']', stdout);
+    fprintf (stdout, " %3d%%", percentage);
+  }
+
+  { const guint spacelen = ncolumns - textlen - barlen;
+    printpad (spaces, n_spaces, spacelen);
+  }
+
+  fflush (stdout);
+}
+
+/**
+ * glnx_console_unlock:
+ *
+ * Print a newline, and reset all cached console progress state.
+ *
+ * This function does nothing if stdout is not a tty.
+ */
+void
+glnx_console_unlock (GLnxConsoleRef *console)
+{
+  if (!stdout_is_tty ())
+    return;
+  
+  g_return_if_fail (locked);
+  g_return_if_fail (console->locked);
+
+  current_percent = -1;
+  g_clear_pointer (&current_text, g_free);
+  fputc ('\n', stdout);
+
+  locked = FALSE;
+}
diff --git a/glnx-console.h b/glnx-console.h
new file mode 100644
index 0000000..3dfdf1b
--- /dev/null
+++ b/glnx-console.h
@@ -0,0 +1,47 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2013,2014,2015 Colin Walters <walters verbum org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2 of the licence or (at
+ * your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#pragma once
+
+#include <glnx-backport-autoptr.h>
+
+G_BEGIN_DECLS
+
+struct GLnxConsoleRef {
+  gboolean locked;
+};
+
+typedef struct GLnxConsoleRef GLnxConsoleRef;
+
+void    glnx_console_lock (GLnxConsoleRef *ref);
+
+void    glnx_console_progress_text_percent (const char     *text,
+                                             guint           percentage);
+
+void    glnx_console_unlock (GLnxConsoleRef *ref);
+
+static inline void
+glnx_console_ref_cleanup (GLnxConsoleRef *p)
+{
+  glnx_console_unlock (p);
+}
+G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(GLnxConsoleRef, glnx_console_ref_cleanup)
+
+G_END_DECLS
diff --git a/libglnx.h b/libglnx.h
index e74eeda..8ff787c 100644
--- a/libglnx.h
+++ b/libglnx.h
@@ -31,5 +31,6 @@ G_BEGIN_DECLS
 #include <glnx-dirfd.h>
 #include <glnx-shutil.h>
 #include <glnx-xattrs.h>
+#include <glnx-console.h>
 
 G_END_DECLS