printf hooks refactored to increase portability (i.e. support for platforms without glibc-compatible customizable printf - the Vstr string library is currently required on such platforms).

2009-03-12 18:07:32 +00:00
parent 9086102dfd
commit d25ce3701e
33 changed files with 678 additions and 443 deletions
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2009 Tobias Brunner
 * Copyright (C) 2006-2008 Martin Willi
 * Hochschule fuer Technik Rapperswil
 *
@@ -18,8 +19,17 @@
 #include "printf_hook.h"

 #include <utils.h>
+#include <debug.h>
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>

 typedef struct private_printf_hook_t private_printf_hook_t;
+typedef struct printf_hook_handler_t printf_hook_handler_t;
+
+#define PRINTF_BUF_LEN 8192
+#define ARGS_MAX 3

 /**
 * private data of printf_hook
@@ -32,13 +42,340 @@ struct private_printf_hook_t {
 	printf_hook_t public;
 };

+/**
+ * struct with information about a registered handler
+ */
+struct printf_hook_handler_t {
+	
+	/**
+	 * callback function
+	 */
+	printf_hook_function_t hook;
+	
+	/**
+	 * number of arguments
+	 */
+	int numargs;
+	
+	/**
+	 * types of the arguments
+	 */
+	int argtypes[ARGS_MAX];
+
+#ifndef HAVE_PRINTF_HOOKS
+	/**
+	 * name required for Vstr
+	 */
+	char *name;
+#endif
+};
+
+/* A-Z | 6 other chars | a-z */
+#define NUM_HANDLERS 58
+static printf_hook_handler_t *printf_hooks[NUM_HANDLERS];
+
+#define SPEC_TO_INDEX(spec) ((int)(spec) - (int)'A')
+#define IS_VALID_SPEC(spec) (SPEC_TO_INDEX(spec) > -1 && SPEC_TO_INDEX(spec) < NUM_HANDLERS)
+
+#ifdef HAVE_PRINTF_HOOKS
+
+/**
+ * Printf hook print function. This is actually of type "printf_function",
+ * however glibc does it typedef to function, but uclibc to a pointer.
+ * So we redefine it here.
+ */
+static int custom_print(FILE *stream, const struct printf_info *info,
+						const void *const *args)
+{
+	int written;
+	char buf[PRINTF_BUF_LEN];
+	printf_hook_spec_t spec;
+	printf_hook_handler_t *handler = printf_hooks[SPEC_TO_INDEX(info->spec)];
+	
+	spec.hash = info->alt;
+	spec.minus = info->left;
+	spec.width = info->width;
+	
+	written = handler->hook(buf, sizeof(buf), &spec, args);
+	if (written > 0)
+	{
+		fwrite(buf, 1, written, stream);
+	}
+	return written;
+}
+
+/**
+ * Printf hook arginfo function, which is actually of type
+ * "printf_arginfo_function".
+ */
+static int custom_arginfo(const struct printf_info *info, size_t n, int *argtypes)
+{
+	int i;
+	printf_hook_handler_t *handler = printf_hooks[SPEC_TO_INDEX(info->spec)];
+	
+	if (handler->numargs <= n)
+	{
+		for (i = 0; i < handler->numargs; ++i)
+		{
+			argtypes[i] = handler->argtypes[i];
+		}
+	}
+	return handler->numargs;
+}
+
+#else
+
+#include <errno.h>
+#include <unistd.h> /* for STDOUT_FILENO */
+
+/**
+ * Vstr custom format specifier callback function.
+ */
+static int custom_fmt_cb(Vstr_base *base, size_t pos, Vstr_fmt_spec *fmt_spec)
+{
+	int i, written;
+	char buf[PRINTF_BUF_LEN];
+	const void *args[ARGS_MAX];
+	printf_hook_spec_t spec;
+	printf_hook_handler_t *handler = printf_hooks[SPEC_TO_INDEX(fmt_spec->name[0])];
+	
+	for (i = 0; i < handler->numargs; i++)
+	{
+		switch(handler->argtypes[i])
+		{
+			case PRINTF_HOOK_ARGTYPE_INT:
+				args[i] = VSTR_FMT_CB_ARG_PTR(fmt_spec, i);
+				break;
+			case PRINTF_HOOK_ARGTYPE_POINTER:
+				args[i] = &VSTR_FMT_CB_ARG_PTR(fmt_spec, i);
+				break;
+		}
+	}
+	
+	spec.hash = fmt_spec->fmt_hash;
+	spec.minus = fmt_spec->fmt_minus;
+	spec.width = fmt_spec->fmt_field_width;
+	
+	written = handler->hook(buf, sizeof(buf), &spec, args);
+	if (written > 0)
+	{
+		vstr_add_buf(base, pos, buf, written);
+	}
+	return TRUE;
+}
+
+/**
+ * Add a custom format handler to the given Vstr_conf object 
+ */
+static void vstr_fmt_add_handler(Vstr_conf *conf, printf_hook_handler_t *handler)
+{
+	int *at = handler->argtypes;
+	switch(handler->numargs)
+	{
+		case 1:
+			vstr_fmt_add(conf, handler->name, custom_fmt_cb, at[0], VSTR_TYPE_FMT_END);
+			break;
+		case 2:
+			vstr_fmt_add(conf, handler->name, custom_fmt_cb, at[0], at[1], VSTR_TYPE_FMT_END);
+			break;
+		case 3:
+			vstr_fmt_add(conf, handler->name, custom_fmt_cb, at[0], at[1], at[2], VSTR_TYPE_FMT_END);
+			break;
+	}
+}
+
+/**
+ * Management of thread-specific Vstr_conf objects
+ */
+#include <pthread.h>
+
+static pthread_key_t vstr_conf_key;
+static pthread_once_t vstr_conf_key_once = PTHREAD_ONCE_INIT;
+
+static void init_vstr_conf_key(void)
+{
+	pthread_key_create(&vstr_conf_key, (void*)vstr_free_conf);
+}
+
+static Vstr_conf *create_vstr_conf()
+{
+	int i;
+	Vstr_conf *conf = vstr_make_conf();
+	vstr_cntl_conf(conf, VSTR_CNTL_CONF_SET_FMT_CHAR_ESC, '%');
+	vstr_cntl_conf(conf, VSTR_CNTL_CONF_SET_TYPE_GRPALLOC_CACHE,
+						 VSTR_TYPE_CNTL_CONF_GRPALLOC_CSTR);
+	vstr_cntl_conf(conf, VSTR_CNTL_CONF_SET_NUM_BUF_SZ, PRINTF_BUF_LEN);
+	for (i = 0; i < NUM_HANDLERS; ++i)
+	{
+		printf_hook_handler_t *handler = printf_hooks[i];
+		if (handler)
+		{
+			vstr_fmt_add_handler(conf, handler);
+		}
+	}
+	return conf;
+}
+
+static inline Vstr_conf *get_vstr_conf()
+{
+	Vstr_conf *conf;
+	pthread_once(&vstr_conf_key_once, init_vstr_conf_key);
+	conf = (Vstr_conf*)pthread_getspecific(vstr_conf_key);
+	if (!conf)
+	{
+		conf = create_vstr_conf();
+		pthread_setspecific(vstr_conf_key, conf);
+	}
+	return conf;
+}
+
+/**
+ * Wrapper functions for printf and alike
+ */
+int vstr_wrapper_printf(const char *format, ...)
+{
+	int written;
+	va_list args;
+	va_start(args, format);
+	written = vstr_wrapper_vprintf(format, args);
+	va_end(args);
+	return written;
+}
+int vstr_wrapper_fprintf(FILE *stream, const char *format, ...)
+{
+	int written;
+	va_list args;
+	va_start(args, format);
+	written = vstr_wrapper_vfprintf(stream, format, args);
+	va_end(args);
+	return written;
+}
+int vstr_wrapper_sprintf(char *str, const char *format, ...)
+{
+	int written;
+	va_list args;
+	va_start(args, format);
+	written = vstr_wrapper_vsprintf(str, format, args);
+	va_end(args);
+	return written;
+}
+int vstr_wrapper_snprintf(char *str, size_t size, const char *format, ...)
+{
+	int written;
+	va_list args;
+	va_start(args, format);
+	written = vstr_wrapper_vsnprintf(str, size, format, args);
+	va_end(args);
+	return written;
+}
+static inline int vstr_wrapper_vprintf_internal(int fd, const char *format,
+												va_list args)
+{
+	int written;
+	Vstr_conf *conf = get_vstr_conf();
+	Vstr_base *s = vstr_make_base(conf);
+	vstr_add_vfmt(s, 0, format, args);
+	written = s->len;
+	while (s->len)
+	{
+		if (!vstr_sc_write_fd(s, 1, s->len, fd, NULL))
+		{
+			if (errno != EAGAIN && errno != EINTR)
+			{
+				written -= s->len;
+				break;
+			}
+		}
+	}
+	vstr_free_base(s);
+	return written;
+}
+int vstr_wrapper_vprintf(const char *format, va_list args)
+{
+	return vstr_wrapper_vprintf_internal(STDOUT_FILENO, format, args);
+}
+int vstr_wrapper_vfprintf(FILE *stream, const char *format, va_list args)
+{
+	return vstr_wrapper_vprintf_internal(fileno(stream), format, args);
+}
+static inline int vstr_wrapper_vsnprintf_internal(char *str, size_t size,
+												  const char *format,
+												  va_list args)
+{
+	int written;
+	Vstr_conf *conf = get_vstr_conf();
+	Vstr_base *s = vstr_make_base(conf);
+	vstr_add_vfmt(s, 0, format, args);
+	written = s->len;
+	vstr_export_cstr_buf(s, 1, s->len, str, (size > 0) ? size : s->len + 1);
+	vstr_free_base(s);
+	return written;
+}
+int vstr_wrapper_vsprintf(char *str, const char *format, va_list args)
+{
+	return vstr_wrapper_vsnprintf_internal(str, 0, format, args);
+}
+int vstr_wrapper_vsnprintf(char *str, size_t size, const char *format,
+						   va_list args)
+{
+	return (size > 0) ? vstr_wrapper_vsnprintf_internal(str, size, format, args) : 0;
+}
+
+#endif
+
 /**
 * Implementation of printf_hook_t.add_handler.
 */
-static void add_handler(private_printf_hook_t *this, char spec, 
-						printf_hook_functions_t hook)
+static void add_handler(private_printf_hook_t *this, char spec,
+						printf_hook_function_t hook, ...)
 {
-	register_printf_function(spec, hook.print, hook.arginfo);
+	int i = -1;
+	printf_hook_handler_t *handler;
+	printf_hook_argtype_t argtype;
+	va_list args;
+	
+	if (!IS_VALID_SPEC(spec))
+	{
+		DBG1("'%c' is not a valid printf hook specifier, not registered!", spec);
+		return;
+	}
+	
+	handler = malloc_thing(printf_hook_handler_t); 
+	handler->hook = hook;
+	
+	va_start(args, hook);
+	while ((argtype = va_arg(args, printf_hook_argtype_t)) != PRINTF_HOOK_ARGTYPE_END)
+	{
+		if (++i >= ARGS_MAX)
+		{
+			DBG1("Too many arguments for printf hook with specifier '%c', not registered!", spec);
+			va_end(args);
+			free(handler);
+			return;
+		}
+		handler->argtypes[i] = argtype;
+	}
+	va_end(args);
+	
+	handler->numargs = i + 1;
+	
+	if (handler->numargs > 0)
+	{
+#ifdef HAVE_PRINTF_HOOKS
+		register_printf_function(spec, custom_print, custom_arginfo);
+#else
+		Vstr_conf *conf = get_vstr_conf();
+		handler->name = malloc(2);
+		handler->name[0] = spec;
+		handler->name[1] = '\0';
+		vstr_fmt_add_handler(conf, handler);
+#endif
+		printf_hooks[SPEC_TO_INDEX(spec)] = handler;
+	}
+	else
+	{
+		free(handler);
+	}
 }

 /**
@@ -46,6 +383,30 @@ static void add_handler(private_printf_hook_t *this, char spec,
 */
 static void destroy(private_printf_hook_t *this)
 {
+	int i;
+#ifndef HAVE_PRINTF_HOOKS
+	Vstr_conf *conf = get_vstr_conf();
+#endif
+	
+	for (i = 0; i < NUM_HANDLERS; ++i)
+	{
+		printf_hook_handler_t *handler = printf_hooks[i];
+		if (handler)
+		{
+#ifndef HAVE_PRINTF_HOOKS
+			vstr_fmt_del(conf, handler->name);
+			free(handler->name);
+#endif
+			free(handler);
+		}
+	}
+	
+#ifndef HAVE_PRINTF_HOOKS
+	/* freeing the Vstr_conf of the main thread */
+	pthread_key_delete(vstr_conf_key);
+	vstr_free_conf(conf);
+	vstr_exit();
+#endif
 	free(this);
 }

@@ -56,9 +417,19 @@ printf_hook_t *printf_hook_create()
 {
 	private_printf_hook_t *this = malloc_thing(private_printf_hook_t);
 	
-	this->public.add_handler = (void(*)(printf_hook_t*, char, printf_hook_functions_t))add_handler;
+	this->public.add_handler = (void(*)(printf_hook_t*, char, printf_hook_function_t, ...))add_handler;
 	this->public.destroy = (void(*)(printf_hook_t*))destroy;
 	
+	memset(printf_hooks, 0, sizeof(printf_hooks));
+	
+#ifndef HAVE_PRINTF_HOOKS
+	if (!vstr_init())
+	{
+		DBG1("failed to initialize Vstr library!");
+		free(this);
+		return NULL;
+	}
+#endif
 	
 	return &this->public;
 }