add start of new classes for handling logging

4 files changed, 574 insertions, 0 deletions

diff --git a/src/ply-logger.c b/src/ply-logger.c
new file mode 100644
index 0000000..bf9358a
--- /dev/null
+++ b/src/ply-logger.c
@@ -0,0 +1,448 @@
+/* ply-logger.c - logging and tracing facilities
+ *
+ * Copyright (C) 2005 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.  
+ */
+#include "config.h"
+#include "ply-logger.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_LOGGER_OPEN_FLAGS 
+#define PLY_LOGGER_OPEN_FLAGS (O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW)
+#endif
+
+#ifndef PLY_LOGGER_MAX_INJECTION_SIZE
+#define PLY_LOGGER_MAX_INJECTION_SIZE 1024
+#endif 
+
+#ifndef PLY_LOGGER_MAX_BUFFER_CAPACITY
+#define PLY_LOGGER_MAX_BUFFER_CAPACITY (8 * 4096)
+#endif
+
+struct _ply_logger 
+{
+  int output_fd;
+  char *filename;
+
+  char *buffer;
+  size_t buffer_size;
+  size_t buffer_capacity;
+
+  uint32_t is_enabled : 1;
+  uint32_t tracing_is_enabled : 1;
+};
+
+static bool ply_text_is_loggable (const char *string,
+                                  ssize_t     length);
+static void ply_logger_write_exception (ply_logger_t   *logger,
+                                        const char     *string);
+static bool ply_logger_write (ply_logger_t   *logger,
+                              const char     *string,
+                              size_t          length,
+                              bool            should_report_failures);
+
+static bool ply_logger_buffer (ply_logger_t   *logger,
+                               const char     *string,
+                               size_t          length);
+static bool ply_logger_flush_buffer (ply_logger_t *logger);
+
+static bool
+ply_text_is_loggable (const char *string,
+                      ssize_t     length)
+{
+  /* I guess we should let everything through since there
+   * isn't really any specified encoding
+   */
+
+  return true;
+}
+
+static void
+ply_logger_write_exception (ply_logger_t   *logger,
+                            const char     *string)
+{
+  char *message;
+  int number_of_bytes;
+
+  if (!ply_text_is_loggable (string, -1))
+    return;
+
+  message = NULL;
+  asprintf (&message, 
+            "[couldn't write a log entry: %s]\n%n",
+            string, &number_of_bytes);
+
+  assert (message != NULL);
+
+  ply_logger_write (logger, message, number_of_bytes, false);
+  free (message);
+}
+
+static bool
+ply_logger_write (ply_logger_t *logger,
+                  const char   *string,
+                  size_t        length,
+                  bool          should_report_failures)
+{
+  if (!ply_text_is_loggable (string, length))
+    {
+      if (should_report_failures)
+        ply_logger_write_exception (logger,
+                                    "log text contains unloggable bytes");
+      /* we return true here, because returning false would mean
+       * "you aren't allowed to write to the log file anymore"
+       */
+      return true;
+    }
+
+  if (!ply_write (logger->output_fd, string, length))
+    {
+      if (should_report_failures)
+        ply_logger_write_exception (logger, strerror (errno));
+
+      return false;
+    }
+
+  return true;
+}
+
+static bool
+ply_logger_flush_buffer (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+
+  if (logger->buffer_size == 0)
+    return true;
+
+  if (!ply_logger_write (logger, logger->buffer, logger->buffer_size, true))
+    return false;
+
+  memset (logger->buffer, '\0', logger->buffer_size);
+  logger->buffer_size = 0;
+
+  return true;
+}
+
+static bool
+ply_logger_increase_buffer_size (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+
+  if ((logger->buffer_capacity * 2) > PLY_LOGGER_MAX_BUFFER_CAPACITY)
+    return false;
+
+  logger->buffer_capacity *= 2;
+
+  logger->buffer = realloc (logger->buffer, logger->buffer_capacity);
+  return true;
+}
+
+static void
+ply_logger_decapitate_buffer (ply_logger_t *logger,
+                              size_t        bytes_in_head)
+{
+  assert (logger != NULL);
+
+  bytes_in_head = MIN (logger->buffer_size, bytes_in_head);
+
+  if (bytes_in_head == logger->buffer_size)
+    logger->buffer_size = 0;
+  else
+    {
+      memmove (logger->buffer, logger->buffer + bytes_in_head,
+               logger->buffer_size - bytes_in_head);
+      logger->buffer_size -= bytes_in_head;
+    }
+}
+
+static bool 
+ply_logger_buffer (ply_logger_t *logger,
+                   const char   *string,
+                   size_t        length)
+{
+  assert (logger != NULL);
+
+  if ((logger->buffer_size + length) >= logger->buffer_capacity)
+    {
+      if (!ply_logger_increase_buffer_size (logger))
+        {
+          ply_logger_decapitate_buffer (logger, length);
+          
+          if ((logger->buffer_size + length) >= logger->buffer_capacity)
+            if (!ply_logger_increase_buffer_size (logger))
+              return false;
+        }
+    }
+
+  assert (logger->buffer_size + length < logger->buffer_capacity);
+
+  memcpy (logger->buffer + logger->buffer_size, 
+          string, length);
+
+  logger->buffer_size += length;
+
+  return true;
+}
+
+ply_logger_t *
+ply_logger_new (void)
+{
+  ply_logger_t *logger;
+
+  logger = calloc (1, sizeof (ply_logger_t));
+
+  logger->output_fd = STDOUT_FILENO;
+  logger->filename = NULL;
+  logger->is_enabled = true;
+  logger->tracing_is_enabled = false;
+
+  logger->buffer_capacity = 4096;
+  logger->buffer = calloc (1, logger->buffer_capacity);
+  logger->buffer_size = 0;
+
+  return logger;
+}
+
+ply_logger_t *
+ply_logger_get_default (void)
+{
+  static ply_logger_t *ply_logger = NULL;
+
+  if (ply_logger == NULL)
+    ply_logger = ply_logger_new ();
+
+  return ply_logger;
+}
+
+void
+ply_logger_free (ply_logger_t *logger)
+{
+  if (logger == NULL)
+    return;
+
+  if (logger->output_fd >= 0)
+    {
+      if (ply_logger_is_logging (logger))
+        ply_logger_flush (logger);
+      close (logger->output_fd);
+    }
+
+  free (logger->filename);
+  free (logger);
+}
+
+bool 
+ply_logger_open_file (ply_logger_t    *logger,
+                      const char      *filename)
+{
+  int fd;
+
+  assert (logger != NULL);
+  assert (filename != NULL);
+
+  fd = open (filename, PLY_LOGGER_OPEN_FLAGS, 0600);
+
+  if (fd < 0)
+    return false;
+
+  ply_logger_set_output_fd (logger, fd);
+
+  free (logger->filename);
+
+  logger->filename = strdup (filename);
+
+  return true;
+}
+
+void
+ply_logger_close_file (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+
+  close (logger->output_fd);
+  ply_logger_set_output_fd (logger, -1);
+}
+
+void 
+ply_logger_set_output_fd (ply_logger_t *logger,
+                          int           fd)
+{
+  assert (logger != NULL);
+
+  logger->output_fd = fd;
+}
+
+int 
+ply_logger_get_output_fd (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+
+  return logger->output_fd;
+}
+
+bool 
+ply_logger_flush (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+  assert (logger->output_fd >= 0);
+  assert (ply_logger_is_logging (logger));
+
+  if (!ply_logger_flush_buffer (logger))
+    return false;
+
+  if ((fdatasync (logger->output_fd) < 0) &&
+      ((errno != EROFS) && (errno != EINVAL)))
+    return false;
+
+  return true;
+}
+
+void 
+ply_logger_toggle_logging (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+
+  logger->is_enabled = !logger->is_enabled;
+}
+
+bool 
+ply_logger_is_logging (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+
+  return logger->is_enabled != false;
+}
+
+static bool
+ply_logger_validate_format_string (ply_logger_t   *logger,
+                                   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_logger_inject_with_non_literal_format_string (ply_logger_t   *logger,
+                                                  const char     *format,
+                                                  ...)
+{
+  va_list args;
+  size_t string_size;
+  char write_buffer[PLY_LOGGER_MAX_INJECTION_SIZE] = "";
+
+  assert (logger != NULL);
+
+  if (!ply_logger_is_logging (logger))
+    return;
+
+  if (!ply_logger_validate_format_string (logger, format))
+    {
+      ply_logger_write_exception (logger, "log format string invalid");
+      return;
+    }
+
+  va_start (args, format);
+  string_size = vsnprintf (write_buffer, 0, format, args) + 1;
+  va_end (args);
+
+  if (string_size > PLY_LOGGER_MAX_INJECTION_SIZE)  
+    {
+      ply_logger_write_exception (logger, "log text too long");
+      return;
+    }
+
+  va_start (args, format);
+  vsnprintf (write_buffer, PLY_LOGGER_MAX_INJECTION_SIZE,
+             format, args);
+  va_end (args);
+
+  ply_logger_buffer (logger, write_buffer, string_size - 1);
+}
+
+#ifdef PLY_ENABLE_TRACING
+void
+ply_logger_toggle_tracing (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+
+  logger->tracing_is_enabled = !logger->tracing_is_enabled;
+}
+
+bool
+ply_logger_is_tracing_enabled (ply_logger_t *logger)
+{
+  assert (logger != NULL);
+
+  return logger->tracing_is_enabled != false;
+} 
+#endif /* PLY_ENABLE_TRACING */ 
+
+#ifdef PLY_LOGGER_ENABLE_TEST
+
+int
+main (int    argc, 
+      char **argv)
+{
+  int exit_code;
+  ply_logger_t *logger;
+  
+  exit_code = 0;
+  logger = ply_logger_new ();
+
+  ply_logger_inject (logger, "yo yo yo\n");
+  ply_logger_set_output_fd (logger, 1);
+  ply_logger_inject (logger, "yo yo yo yo\n");
+  ply_logger_flush (logger);
+  ply_logger_free (logger);
+
+  return exit_code;
+}
+
+#endif /* PLY_LOGGER_ENABLE_TEST */
+/* vim: set ts=4 sw=4 expandtab autoindent cindent cino={.5s,(0: */
diff --git a/src/ply-logger.h b/src/ply-logger.h
new file mode 100644
index 0000000..077f8ca
--- /dev/null
+++ b/src/ply-logger.h
@@ -0,0 +1,115 @@
+/* ply-logger.h - logging and tracing facilities
+ *
+ * Copyright (C) 2007 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_LOGGER_H
+#define PLY_LOGGER_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+typedef struct _ply_logger ply_logger_t;
+
+#ifndef PLY_HIDE_FUNCTION_DECLARATIONS
+ply_logger_t *ply_logger_new (void);
+void ply_logger_free (ply_logger_t *logger);
+bool ply_logger_open_file (ply_logger_t *logger,
+                           const char   *filename);
+void ply_logger_close_file (ply_logger_t    *logger);
+void ply_logger_set_output_fd (ply_logger_t *logger,
+                               int           fd);
+int ply_logger_get_output_fd (ply_logger_t *logger);
+bool ply_logger_flush (ply_logger_t *logger);
+void ply_logger_toggle_logging (ply_logger_t *logger);
+bool ply_logger_is_logging (ply_logger_t *logger);
+
+#define ply_logger_inject(logger, format, args...)                             \
+        ply_logger_inject_with_non_literal_format_string (logger,              \
+                                                          format "", ##args) 
+
+__attribute__((__format__ (__printf__, 2, 3)))
+void ply_logger_inject_with_non_literal_format_string (ply_logger_t   *logger,
+                                                       const char *format, ...);
+                                                       
+ply_logger_t *ply_logger_get_default (void);
+/* tracing is a debugging facility that incurs a hefty performance hit on the
+ * program, so we conditionally compile support for it
+ */
+#ifdef PLY_ENABLE_TRACING
+void ply_logger_toggle_tracing (ply_logger_t *logger);
+bool ply_logger_is_tracing_enabled (ply_logger_t *logger);
+
+#define ply_logger_trace(logger, format, args...)                              \
+do                                                                             \
+  {                                                                            \
+    static const char *_function_suffix = "";                                  \
+    const char *_function_name = "";                                           \
+    double _timestamp;                                                         \
+    pid_t _pid;                                                                \
+    int _old_errno;                                                            \
+    _old_errno = errno;                                                        \
+    if (ply_logger_is_tracing_enabled (logger))                                \
+      {                                                                        \
+        ply_logger_flush_to_disk (logger);                                     \
+        _pid = getpid ();                                                      \
+        _timestamp = ply_get_timestamp ();                                     \
+        errno = _old_errno;                                                    \
+        ply_logger_inject (logger,                                             \
+                           "|pid: %d| <%.4f> [%s] %45.45s:" format "\n",       \
+                           _pid, _timestamp, __FILE__, __func__, ##args);      \
+        ply_logger_flush_to_disk (logger);                                     \
+      }                                                                        \
+  }                                                                            \
+while (0)
+#else
+#define ply_logger_trace(logger, format, args...)
+#define ply_logger_toggle_tracing(logger)
+#define ply_logger_is_tracing_enabled(logger) (false)
+#endif /* PLY_ENABLE_TRACING */
+
+/* convenience macros
+ */
+#define ply_open_log_file(filename)                                            \
+        ply_logger_open_file (ply_logger_get_default (), filename)
+#define ply_close_log_file()                                                   \
+        ply_logger_close_file (ply_logger_get_default ())
+#define ply_set_logging_fd(fd)                                                 \
+        ply_logger_set_output_fd (ply_logger_get_default (), fd)           
+#define ply_get_logging_fd()                                                   \
+        ply_logger_get_output_fd (ply_logger_get_default ())
+#define ply_flush_log_to_disk()                                                \
+        ply_logger_flush_to_disk (ply_logger_get_default ())
+#define ply_toggle_logging()                                                   \
+        ply_logger_toggle_logging (ply_logger_get_default ())
+#define ply_is_logging()                                                       \
+        ply_logger_is_logging (ply_logger_get_default ())      
+#define ply_log(format, args...)                                               \
+        ply_logger_inject (ply_logger_get_default (), format, ##args)
+
+#define ply_toggle_tracing()                                                   \
+        ply_logger_toggle_tracing (ply_logger_get_default ())
+#define ply_is_tracing()                                                       \
+        ply_logger_is_tracing_enabled (ply_logger_get_default ())
+#define ply_trace(format, args...)                                             \
+        ply_logger_trace (ply_logger_get_default (), format, ##args)
+#endif /* !PLY_HIDE_FUNCTION_DECLARATIONS */
+
+#endif /* PLY_LOGGER_H */
diff --git a/src/tests/Makefile.am b/src/tests/Makefile.am
index a99e0b5..0e58d71 100644
--- a/src/tests/Makefile.am
+++ b/src/tests/Makefile.am
@@ -9,5 +9,6 @@ include $(srcdir)/ply-image-test.am
 include $(srcdir)/ply-terminal-test.am
 include $(srcdir)/ply-terminal-session-test.am
 include $(srcdir)/ply-init-control-test.am
+include $(srcdir)/ply-logger-test.am
 
 noinst_PROGRAMS = $(TESTS)
diff --git a/src/tests/ply-logger-test.am b/src/tests/ply-logger-test.am
new file mode 100644
index 0000000..7433056
--- /dev/null
+++ b/src/tests/ply-logger-test.am
@@ -0,0 +1,10 @@
+TESTS += ply-logger-test
+
+ply_logger_test_CFLAGS = $(PLYMOUTH_CFLAGS) -DPLY_LOGGER_ENABLE_TEST
+ply_logger_test_LDADD = $(PLYMOUTH_LIBS)
+
+ply_logger_test_SOURCES =                                                     \
+                          $(srcdir)/../ply-utils.h                            \
+                          $(srcdir)/../ply-utils.c                            \
+                          $(srcdir)/../ply-logger.h                           \
+                          $(srcdir)/../ply-logger.c