[gtk/wip/otte/json: 2/3] Add GtkJsonPrinter

[Benjamin Otte <otte src gnome org>]

commit 5d671653a7fd4e79fabd20738f46d6e237d03815
Author: Benjamin Otte <otte redhat com>
Date:   Thu Nov 25 06:30:52 2021 +0100

    Add GtkJsonPrinter

 gtk/css/gtkjsonprinter.c        | 357 ++++++++++++++++++++++++++++++++++++++++
 gtk/css/gtkjsonprinterprivate.h |  70 ++++++++
 gtk/css/meson.build             |   1 +
 3 files changed, 428 insertions(+)
---
diff --git a/gtk/css/gtkjsonprinter.c b/gtk/css/gtkjsonprinter.c
new file mode 100644
index 0000000000..698055b747
--- /dev/null
+++ b/gtk/css/gtkjsonprinter.c
@@ -0,0 +1,357 @@
+/*
+ * Copyright © 2021 Benjamin Otte
+ *
+ * This library 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 2.1 of the License, 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, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte gnome org>
+ */
+
+
+#include "config.h"
+
+#include "gtkjsonprinterprivate.h"
+
+typedef struct _GtkJsonBlock GtkJsonBlock;
+typedef struct _GtkJsonReader GtkJsonReader;
+
+struct _GtkJsonReader
+{
+  const guchar *data;
+  const guchar *end;
+
+  gsize lines;
+  const guchar *line_start;
+};
+
+typedef enum {
+  GTK_JSON_BLOCK_TOPLEVEL,
+  GTK_JSON_BLOCK_OBJECT,
+  GTK_JSON_BLOCK_ARRAY,
+} GtkJsonBlockType;
+
+struct _GtkJsonBlock
+{
+  GtkJsonBlockType type;
+  gsize n_elements; /* number of elements already written */
+};
+
+struct _GtkJsonPrinter
+{
+  GtkJsonPrinterFlags flags;
+
+  GtkJsonPrinterWriteFunc write_func;
+  gpointer user_data;
+  GDestroyNotify user_destroy;
+
+  GtkJsonBlock *block; /* current block */
+  GtkJsonBlock *blocks; /* blocks array */
+  GtkJsonBlock *blocks_end; /* blocks array */
+  GtkJsonBlock blocks_preallocated[128]; /* preallocated */
+};
+
+static void
+gtk_json_printer_push_block (GtkJsonPrinter   *self,
+                             GtkJsonBlockType  type)
+{
+  self->block++;
+  if (self->block == self->blocks_end)
+    {
+      gsize old_size = self->blocks_end - self->blocks;
+      gsize new_size = old_size + 128;
+
+      if (self->blocks == self->blocks_preallocated)
+        {
+          self->blocks = g_new (GtkJsonBlock, new_size);
+          memcpy (self->blocks, self->blocks_preallocated, sizeof (GtkJsonBlock) * G_N_ELEMENTS 
(self->blocks_preallocated));
+        }
+      else
+        {
+          self->blocks = g_renew (GtkJsonBlock, self->blocks, new_size);
+        }
+      self->blocks_end = self->blocks + new_size;
+      self->block = self->blocks + old_size;
+    }
+
+  self->block->type = type;
+  self->block->n_elements = 0;
+}
+                     
+static void
+gtk_json_printer_pop_block (GtkJsonPrinter *self)
+{
+  g_assert (self->block > self->blocks);
+  self->block--;
+}
+
+GtkJsonPrinter *
+gtk_json_printer_new (GtkJsonPrinterFlags     flags,
+                      GtkJsonPrinterWriteFunc write_func,
+                      gpointer                data,
+                      GDestroyNotify          destroy)
+{
+  GtkJsonPrinter *self;
+
+  g_return_val_if_fail (write_func, NULL);
+
+  self = g_slice_new0 (GtkJsonPrinter);
+
+  self->flags = flags;
+  self->write_func = write_func;
+  self->user_data = data;
+  self->user_destroy = destroy;
+
+  self->blocks = self->blocks_preallocated;
+  self->blocks_end = self->blocks + G_N_ELEMENTS (self->blocks_preallocated);
+  self->block = self->blocks;
+  self->block->type = GTK_JSON_BLOCK_TOPLEVEL;
+
+  return self;
+}
+
+void
+gtk_json_printer_free (GtkJsonPrinter *self)
+{
+  g_return_if_fail (self != NULL);
+
+  if (self->user_destroy)
+    self->user_destroy (self->user_data);
+
+  if (self->blocks != self->blocks_preallocated)
+    g_free (self->blocks);
+
+  g_slice_free (GtkJsonPrinter, self);
+}
+
+static gboolean
+gtk_json_printer_has_flag (GtkJsonPrinter      *self,
+                           GtkJsonPrinterFlags  flag)
+{
+  return (self->flags & flag) ? TRUE : FALSE;
+}
+                           
+gsize
+gtk_json_printer_get_depth (GtkJsonPrinter *self)
+{
+  return self->block - self->blocks;
+}
+
+gsize
+gtk_json_printer_get_n_elements (GtkJsonPrinter *self)
+{
+  return self->block->n_elements;
+}
+
+static void
+gtk_json_printer_write (GtkJsonPrinter *self,
+                        const char     *s)
+{
+  self->write_func (self, s, self->user_data);
+}
+
+static char *
+gtk_json_printer_escape_string (GtkJsonPrinter *self,
+                                const char     *str)
+{
+  GString *string;
+
+  string = g_string_new (NULL);
+  string = g_string_append_c (string, '"');
+
+  for (; *str != '\0'; str = g_utf8_next_char (str))
+    {
+      switch (*str)
+        {
+          case '"':
+            g_string_append (string, "\\\"");
+            break;
+          case '\\':
+            g_string_append (string, "\\\\");
+            break;
+          case '\b':
+            g_string_append (string, "\\b");
+            break;
+          case '\f':
+            g_string_append (string, "\\f");
+            break;
+          case '\n':
+            g_string_append (string, "\\n");
+            break;
+          case '\r':
+            g_string_append (string, "\\r");
+            break;
+          case '\t':
+            g_string_append (string, "\\t");
+            break;
+          default:
+            if ((int) *str < 0x20)
+              {
+                if ((guint) *str < 0x20 || gtk_json_printer_has_flag (self, GTK_JSON_PRINTER_ASCII))
+                  g_string_append_printf (string, "\\u%04X", g_utf8_get_char (str));
+                else
+                  g_string_append_unichar (string, g_utf8_get_char (str));
+              }
+            else
+              g_string_append_c (string, *str);
+        }
+    }
+
+  string = g_string_append_c (string, '"');
+  return g_string_free (string, FALSE);
+}
+
+static void
+gtk_json_printer_newline (GtkJsonPrinter *self)
+{
+  gsize depth;
+
+  if (!gtk_json_printer_has_flag (self, GTK_JSON_PRINTER_PRETTY))
+    return;
+
+  gtk_json_printer_write (self, "\n");
+  for (depth = gtk_json_printer_get_depth (self); depth-->0;)
+    gtk_json_printer_write (self, "  ");
+}
+
+static void
+gtk_json_printer_begin_member (GtkJsonPrinter *self,
+                               const char     *name)
+{
+  if (gtk_json_printer_get_n_elements (self) > 0)
+    gtk_json_printer_write (self, ",");
+  if (self->block->type != GTK_JSON_BLOCK_TOPLEVEL || gtk_json_printer_get_n_elements (self) > 0)
+    gtk_json_printer_newline (self);
+
+  self->block->n_elements++;
+
+  if (name)
+    {
+      char *escaped = gtk_json_printer_escape_string (self, name);
+      gtk_json_printer_write (self, escaped);
+      g_free (escaped);
+      if (gtk_json_printer_has_flag (self, GTK_JSON_PRINTER_PRETTY))
+        gtk_json_printer_write (self, " : ");
+      else
+        gtk_json_printer_write (self, ":");
+    }
+}
+
+void
+gtk_json_printer_add_boolean (GtkJsonPrinter *self,
+                              const char     *name,
+                              gboolean        value)
+{
+  g_return_if_fail (self != NULL);
+  g_return_if_fail ((self->block->type == GTK_JSON_BLOCK_OBJECT) == (name != NULL));
+
+  gtk_json_printer_begin_member (self, name);
+  gtk_json_printer_write (self, value ? "true" : "false");
+}
+
+void
+gtk_json_printer_add_number (GtkJsonPrinter *self,
+                             const char     *name,
+                             double          value)
+{
+  char buf[G_ASCII_DTOSTR_BUF_SIZE];
+
+  g_return_if_fail (self != NULL);
+  g_return_if_fail ((self->block->type == GTK_JSON_BLOCK_OBJECT) == (name != NULL));
+
+  gtk_json_printer_begin_member (self, name);
+  g_ascii_dtostr (buf, G_ASCII_DTOSTR_BUF_SIZE, value);
+  gtk_json_printer_write (self, buf);
+}
+
+void
+gtk_json_printer_add_string (GtkJsonPrinter *self,
+                             const char     *name,
+                             const char     *s)
+{
+  char *escaped;
+
+  g_return_if_fail (self != NULL);
+  g_return_if_fail ((self->block->type == GTK_JSON_BLOCK_OBJECT) == (name != NULL));
+
+  gtk_json_printer_begin_member (self, name);
+  escaped = gtk_json_printer_escape_string (self, s);
+  gtk_json_printer_write (self, escaped);
+  g_free (escaped);
+}
+
+void
+gtk_json_printer_add_null (GtkJsonPrinter *self,
+                           const char     *name)
+{
+  g_return_if_fail (self != NULL);
+  g_return_if_fail ((self->block->type == GTK_JSON_BLOCK_OBJECT) == (name != NULL));
+
+  gtk_json_printer_begin_member (self, name);
+  gtk_json_printer_write (self, "null");
+}
+
+void
+gtk_json_printer_start_object (GtkJsonPrinter *self,
+                               const char     *name)
+{
+  g_return_if_fail (self != NULL);
+  g_return_if_fail ((self->block->type == GTK_JSON_BLOCK_OBJECT) == (name != NULL));
+
+  gtk_json_printer_begin_member (self, name);
+  gtk_json_printer_write (self, "{");
+  gtk_json_printer_push_block (self, GTK_JSON_BLOCK_OBJECT);
+}
+
+void
+gtk_json_printer_start_array (GtkJsonPrinter *self,
+                              const char     *name)
+{
+  g_return_if_fail (self != NULL);
+  g_return_if_fail ((self->block->type == GTK_JSON_BLOCK_OBJECT) == (name != NULL));
+
+  gtk_json_printer_begin_member (self, name);
+  gtk_json_printer_write (self, "[");
+  gtk_json_printer_push_block (self, GTK_JSON_BLOCK_ARRAY);
+}
+
+void
+gtk_json_printer_end (GtkJsonPrinter *self)
+{
+  const char *bracket;
+  gboolean empty;
+
+  g_return_if_fail (self != NULL);
+
+  switch (self->block->type)
+    {
+    case GTK_JSON_BLOCK_OBJECT:
+      bracket = "}";
+      break;
+    case GTK_JSON_BLOCK_ARRAY:
+      bracket = "]";
+      break;
+    case GTK_JSON_BLOCK_TOPLEVEL:
+    default:
+      g_return_if_reached ();
+    }
+
+  empty = gtk_json_printer_get_n_elements (self) == 0;
+  gtk_json_printer_pop_block (self);
+
+  if (!empty)
+    {
+      gtk_json_printer_newline (self);
+    }
+  gtk_json_printer_write (self, bracket);
+}
+
diff --git a/gtk/css/gtkjsonprinterprivate.h b/gtk/css/gtkjsonprinterprivate.h
new file mode 100644
index 0000000000..24ce9b8af8
--- /dev/null
+++ b/gtk/css/gtkjsonprinterprivate.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright © 2021 Benjamin Otte
+ *
+ * This library 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 2.1 of the License, 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, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Benjamin Otte <otte gnome org>
+ */
+
+
+#ifndef __GTK_JSON_PRINTER_H__
+#define __GTK_JSON_PRINTER_H__
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+typedef struct _GtkJsonPrinter GtkJsonPrinter;
+
+typedef enum {
+  GTK_JSON_PRINTER_PRETTY = (1 << 0),
+  GTK_JSON_PRINTER_ASCII  = (1 << 1),
+} GtkJsonPrinterFlags;
+
+typedef void            (* GtkJsonPrinterWriteFunc)             (GtkJsonPrinter         *printer,
+                                                                 const char             *s,
+                                                                 gpointer                user_data);
+             
+
+GtkJsonPrinter *        gtk_json_printer_new                    (GtkJsonPrinterFlags     flags,
+                                                                 GtkJsonPrinterWriteFunc write_func,
+                                                                 gpointer                data,
+                                                                 GDestroyNotify          destroy);
+void                    gtk_json_printer_free                   (GtkJsonPrinter         *self);
+
+gsize                   gtk_json_printer_get_depth              (GtkJsonPrinter         *self);
+gsize                   gtk_json_printer_get_n_elements         (GtkJsonPrinter         *self);
+
+void                    gtk_json_printer_add_boolean            (GtkJsonPrinter         *self,
+                                                                 const char             *name,
+                                                                 gboolean                value);
+void                    gtk_json_printer_add_number             (GtkJsonPrinter         *self,
+                                                                 const char             *name,
+                                                                 double                  value);
+void                    gtk_json_printer_add_string             (GtkJsonPrinter         *self,
+                                                                 const char             *name,
+                                                                 const char             *s);
+void                    gtk_json_printer_add_null               (GtkJsonPrinter         *self,
+                                                                 const char             *name);
+
+void                    gtk_json_printer_start_object           (GtkJsonPrinter         *self,
+                                                                 const char             *name);
+void                    gtk_json_printer_start_array            (GtkJsonPrinter         *self,
+                                                                 const char             *name);
+void                    gtk_json_printer_end                    (GtkJsonPrinter         *self);
+
+
+G_END_DECLS
+
+#endif /* __GTK_JSON_PRINTER_H__ */
diff --git a/gtk/css/meson.build b/gtk/css/meson.build
index 136672784d..18bc9aafbe 100644
--- a/gtk/css/meson.build
+++ b/gtk/css/meson.build
@@ -10,6 +10,7 @@ gtk_css_private_sources = files([
   'gtkcssserializer.c',
   'gtkcsstokenizer.c',
   'gtkjsonparser.c',
+  'gtkjsonprinter.c',
 ])
 
 gtk_css_public_headers = files([