--- /dev/null
+/* ply-buffer.c - facilities for buffering data
+ *
+ * Copyright (C) 2008 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Written by: Ray Strode <rstrode@redhat.com>
+ */
+#include "config.h"
+#include "ply-buffer.h"
+
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/fcntl.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "ply-utils.h"
+
+#ifndef PLY_BUFFER_MAX_APPEND_SIZE
+#define PLY_BUFFER_MAX_APPEND_SIZE 1024
+#endif
+
+#ifndef PLY_BUFFER_MAX_BUFFER_CAPACITY
+#define PLY_BUFFER_MAX_BUFFER_CAPACITY (8 * 4096)
+#endif
+
+struct _ply_buffer
+{
+ char *data;
+ size_t size;
+ size_t capacity;
+};
+
+static bool
+ply_buffer_increase_capacity (ply_buffer_t *buffer)
+{
+ assert (buffer != NULL);
+
+ if ((buffer->capacity * 2) > PLY_BUFFER_MAX_BUFFER_CAPACITY)
+ return false;
+
+ buffer->capacity *= 2;
+
+ buffer->data = realloc (buffer->data, buffer->capacity);
+ return true;
+}
+
+static void
+ply_buffer_decapitate (ply_buffer_t *buffer,
+ size_t bytes_in_head)
+{
+ assert (buffer != NULL);
+
+ bytes_in_head = MIN (buffer->size, bytes_in_head);
+
+ if (bytes_in_head == buffer->size)
+ buffer->size = 0;
+ else
+ {
+ memmove (buffer->data, buffer->data + bytes_in_head,
+ buffer->size - bytes_in_head);
+ buffer->size -= bytes_in_head;
+ }
+}
+
+ply_buffer_t *
+ply_buffer_new (void)
+{
+ ply_buffer_t *buffer;
+
+ buffer = calloc (1, sizeof (ply_buffer_t));
+
+ buffer->capacity = 4096;
+ buffer->data = calloc (1, buffer->capacity);
+ buffer->size = 0;
+
+ return buffer;
+}
+
+void
+ply_buffer_free (ply_buffer_t *buffer)
+{
+ if (buffer == NULL)
+ return;
+
+ free (buffer->data);
+ free (buffer);
+}
+
+static bool
+ply_buffer_validate_format_string (ply_buffer_t *buffer,
+ const char *format)
+{
+ char *n, *p;
+
+ p = (char *) format;
+
+ /* lame checks to limit the damage
+ * of some potential exploits.
+ */
+ while ((n = strstr (p, "%n")) != NULL)
+ {
+ if (n == format)
+ return false;
+
+ if (n[-1] != '%')
+ return false;
+
+ p = n + 1;
+ }
+
+ return true;
+}
+
+void
+ply_buffer_append_with_non_literal_format_string (ply_buffer_t *buffer,
+ const char *format,
+ ...)
+{
+ va_list args;
+ size_t string_size;
+ char write_buffer[PLY_BUFFER_MAX_APPEND_SIZE] = "";
+
+ assert (buffer != NULL);
+
+ if (!ply_buffer_validate_format_string (buffer, format))
+ return;
+
+ va_start (args, format);
+ string_size = vsnprintf (write_buffer, 0, format, args) + 1;
+ va_end (args);
+
+ if (string_size > PLY_BUFFER_MAX_APPEND_SIZE)
+ return;
+
+ va_start (args, format);
+ vsnprintf (write_buffer, PLY_BUFFER_MAX_APPEND_SIZE,
+ format, args);
+ va_end (args);
+
+ ply_buffer_append_bytes (buffer, write_buffer, string_size - 1);
+}
+
+void
+ply_buffer_append_bytes (ply_buffer_t *buffer,
+ const void *bytes,
+ size_t length)
+{
+ assert (buffer != NULL);
+ assert (bytes != NULL);
+ assert (length != 0);
+
+ if ((buffer->size + length) >= buffer->capacity)
+ {
+ if (!ply_buffer_increase_capacity (buffer))
+ {
+ ply_buffer_decapitate (buffer, length);
+
+ if ((buffer->size + length) >= buffer->capacity)
+ if (!ply_buffer_increase_capacity (buffer))
+ return;
+ }
+ }
+
+ assert (buffer->size + length < buffer->capacity);
+
+ memcpy (buffer->data + buffer->size,
+ bytes, length);
+
+ buffer->size += length;
+}
+
+const char *
+ply_buffer_get_bytes (ply_buffer_t *buffer)
+{
+ assert (buffer != NULL);
+ return buffer->data;
+}
+
+size_t
+ply_buffer_get_size (ply_buffer_t *buffer)
+{
+ return buffer->size;
+}
+
+void
+ply_buffer_clear (ply_buffer_t *buffer)
+{
+ buffer->size = 0;
+}
+
+#ifdef PLY_BUFFER_ENABLE_TEST
+int
+main (int argc,
+ char **argv)
+{
+ int exit_code;
+ ply_buffer_t *buffer;
+
+ exit_code = 0;
+ buffer = ply_buffer_new ();
+
+ ply_buffer_append (buffer, "yo yo yo\n");
+ ply_buffer_free (buffer);
+
+ return exit_code;
+}
+
+#endif /* PLY_BUFFER_ENABLE_TEST */
+/* vim: set ts=4 sw=4 expandtab autoindent cindent cino={.5s,(0: */
--- /dev/null
+/* ply-buffer.h - facilities for buffering data
+ *
+ * Copyright (C) 2008 Ray Strode <rstrode@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+#ifndef PLY_BUFFER_H
+#define PLY_BUFFER_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+typedef struct _ply_buffer ply_buffer_t;
+
+#ifndef PLY_HIDE_FUNCTION_DECLARATIONS
+ply_buffer_t *ply_buffer_new (void);
+void ply_buffer_free (ply_buffer_t *buffer);
+void ply_buffer_append_bytes (ply_buffer_t *buffer,
+ const void *bytes,
+ size_t number_of_bytes);
+#define ply_buffer_append(buffer, format, args...) \
+ ply_buffer_append_with_non_literal_format_string (buffer, \
+ format "", ##args)
+__attribute__((__format__ (__printf__, 2, 3)))
+void ply_buffer_append_with_non_literal_format_string (ply_buffer_t *buffer,
+ const char *format, ...);
+const char *ply_buffer_get_bytes (ply_buffer_t *buffer);
+size_t ply_buffer_get_size (ply_buffer_t *buffer);
+void ply_buffer_clear (ply_buffer_t *buffer);
+#endif
+
+#endif /* PLY_BUFFER_H */
+/* vim: set ts=4 sw=4 expandtab autoindent cindent cino={.5s,(0: */
projects / thirdparty / plymouth.git / commitdiff
