From 1bdd951ee2fcc906a0394ee0b387e355d2bab850 Mon Sep 17 00:00:00 2001
From: Gustavo Sverzut Barbieri <barbieri@profusion.mobi>
Date: Thu, 8 Dec 2011 13:47:55 -0200
Subject: [PATCH] log: give log function its data instead of kmod_ctx.

This will be the most common use case for logging, also changed
log_stderr() to log_filep() with data being stderr to test it.
---
 libkmod/libkmod-private.h |  2 +-
 libkmod/libkmod.c         | 23 ++++++++++++++---------
 libkmod/libkmod.h         |  5 +++--
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/libkmod/libkmod-private.h b/libkmod/libkmod-private.h
index 578edf2..ce81ae0 100644
--- a/libkmod/libkmod-private.h
+++ b/libkmod/libkmod-private.h
@@ -33,7 +33,7 @@ static __always_inline __printf_format(2, 3) void
 
 #define KMOD_EXPORT __attribute__ ((visibility("default")))
 
-void kmod_log(struct kmod_ctx *ctx,
+void kmod_log(const struct kmod_ctx *ctx,
 		int priority, const char *file, int line, const char *fn,
 		const char *format, ...) __attribute__((format(printf, 6, 7))) __attribute__((nonnull(1, 3, 5)));
 
diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
index 20418e0..b08c6af 100644
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -52,32 +52,34 @@
 struct kmod_ctx {
 	int refcount;
 	int log_priority;
-	void (*log_fn)(struct kmod_ctx *ctx,
+	void (*log_fn)(void *data,
 			int priority, const char *file, int line,
 			const char *fn, const char *format, va_list args);
+	void *log_data;
 	const void *userdata;
 	char *dirname;
 	struct kmod_config *config;
 	struct kmod_hash *modules_by_name;
 };
 
-void kmod_log(struct kmod_ctx *ctx,
+void kmod_log(const struct kmod_ctx *ctx,
 		int priority, const char *file, int line, const char *fn,
 		const char *format, ...)
 {
 	va_list args;
 
 	va_start(args, format);
-	ctx->log_fn(ctx, priority, file, line, fn, format, args);
+	ctx->log_fn(ctx->log_data, priority, file, line, fn, format, args);
 	va_end(args);
 }
 
-static void log_stderr(struct kmod_ctx *ctx,
+static void log_filep(void *data,
 			int priority, const char *file, int line,
 			const char *fn, const char *format, va_list args)
 {
-	fprintf(stderr, "libkmod: %s: ", fn);
-	vfprintf(stderr, format, args);
+	FILE *fp = data;
+	fprintf(fp, "libkmod: %s: ", fn);
+	vfprintf(fp, format, args);
 }
 
 const char *kmod_get_dirname(const struct kmod_ctx *ctx)
@@ -173,7 +175,8 @@ KMOD_EXPORT struct kmod_ctx *kmod_new(const char *dirname)
 		return NULL;
 
 	ctx->refcount = 1;
-	ctx->log_fn = log_stderr;
+	ctx->log_fn = log_filep;
+	ctx->log_data = stderr;
 	ctx->log_priority = LOG_ERR;
 
 	ctx->dirname = get_kernel_release(dirname);
@@ -258,12 +261,14 @@ KMOD_EXPORT struct kmod_ctx *kmod_unref(struct kmod_ctx *ctx)
  *
  **/
 KMOD_EXPORT void kmod_set_log_fn(struct kmod_ctx *ctx,
-					void (*log_fn)(struct kmod_ctx *ctx,
+					void (*log_fn)(void *data,
 						int priority, const char *file,
 						int line, const char *fn,
-						const char *format, va_list args))
+						const char *format, va_list args),
+					const void *data)
 {
 	ctx->log_fn = log_fn;
+	ctx->log_data = (void *)data;
 	INFO(ctx, "custom logging function %p registered\n", log_fn);
 }
 
diff --git a/libkmod/libkmod.h b/libkmod/libkmod.h
index 72f74d0..11cd9b9 100644
--- a/libkmod/libkmod.h
+++ b/libkmod/libkmod.h
@@ -39,10 +39,11 @@ struct kmod_ctx *kmod_new(const char *dirname);
 struct kmod_ctx *kmod_ref(struct kmod_ctx *ctx);
 struct kmod_ctx *kmod_unref(struct kmod_ctx *ctx);
 void kmod_set_log_fn(struct kmod_ctx *ctx,
-			void (*log_fn)(struct kmod_ctx *ctx,
+			void (*log_fn)(void *log_data,
 				int priority, const char *file, int line,
 				const char *fn, const char *format,
-				va_list args));
+				va_list args),
+			const void *data);
 int kmod_get_log_priority(const struct kmod_ctx *ctx);
 void kmod_set_log_priority(struct kmod_ctx *ctx, int priority);
 void *kmod_get_userdata(const struct kmod_ctx *ctx);
-- 
2.7.4