am7xxx: add a simple logging infrastructure

[libam7xxx.git] / src / am7xxx.c

diff --git a/src/am7xxx.c b/src/am7xxx.c
index 114027e..4cfc9a9 100644 (file)
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -19,6 +19,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

+#include <stdarg.h>

 #include <errno.h>
 #include <libusb.h>
 
 #include <errno.h>
 #include <libusb.h>
 


@@ -27,6 +28,27 @@
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 

+/* If we're not using GNU C, elide __attribute__
+ * taken from: http://unixwiz.net/techtips/gnu-c-attributes.html)
+ */
+#ifndef __GNUC__
+#  define  __attribute__(x)  /*NOTHING*/
+#endif
+
+static void log_message(am7xxx_context *ctx,
+                       int level,
+                       const char *function,
+                       int line,
+                       const char *fmt,
+                       ...) __attribute__ ((format (printf, 5, 6)));
+
+#define fatal(...)        log_message(NULL, AM7XXX_LOG_FATAL,   __func__, __LINE__, __VA_ARGS__)
+#define error(ctx, ...)   log_message(ctx,  AM7XXX_LOG_ERROR,   __func__, __LINE__, __VA_ARGS__)
+#define warning(ctx, ...) log_message(ctx,  AM7XXX_LOG_WARNING, __func__, 0,        __VA_ARGS__)
+#define info(ctx, ...)    log_message(ctx,  AM7XXX_LOG_INFO,    __func__, 0,        __VA_ARGS__)
+#define debug(ctx, ...)   log_message(ctx,  AM7XXX_LOG_DEBUG,   __func__, 0,        __VA_ARGS__)
+#define trace(ctx, ...)   log_message(ctx,  AM7XXX_LOG_TRACE,   NULL,     0,        __VA_ARGS__)
+

 struct am7xxx_usb_device_descriptor {
        const char *name;
        uint16_t vendor_id;
 struct am7xxx_usb_device_descriptor {
        const char *name;
        uint16_t vendor_id;


@@ -55,11 +77,13 @@ static struct am7xxx_usb_device_descriptor supported_devices[] = {
 struct _am7xxx_device {
        libusb_device_handle *usb_device;
        uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];
 struct _am7xxx_device {
        libusb_device_handle *usb_device;
        uint8_t buffer[AM7XXX_HEADER_WIRE_SIZE];

+       am7xxx_context *ctx;

        am7xxx_device *next;
 };
 
 struct _am7xxx_context {
        libusb_context *usb_context;
        am7xxx_device *next;
 };
 
 struct _am7xxx_context {
        libusb_context *usb_context;

+       int log_level;

        am7xxx_device *devices_list;
 };
 
        am7xxx_device *devices_list;
 };
 


@@ -321,10 +345,47 @@ static int send_header(am7xxx_device *dev, struct am7xxx_header *h)
        return ret;
 }
 
        return ret;
 }
 

-static am7xxx_device *add_new_device(am7xxx_device **devices_list)
+/* When level == AM7XXX_LOG_FATAL do not check the log_level from the context
+ * and print the message unconditionally, this makes it possible to print
+ * fatal messages even early on initialization, before the context has been
+ * set up */
+static void log_message(am7xxx_context *ctx,
+                       int level,
+                       const char *function,
+                       int line,
+                       const char *fmt,
+                       ...)
+{
+       va_list ap;
+
+       if (level == AM7XXX_LOG_FATAL || (ctx && level <= ctx->log_level)) {
+               if (function) {
+                       fprintf(stderr, "%s", function);
+                       if (line)
+                               fprintf(stderr, "[%d]", line);
+                       fprintf(stderr, ": ");
+               }
+
+               va_start(ap, fmt);
+               vfprintf(stderr, fmt, ap);
+               va_end(ap);
+       }
+
+       return;
+}
+
+static am7xxx_device *add_new_device(am7xxx_context *ctx)

 {
 {

+       am7xxx_device **devices_list;

        am7xxx_device *new_device;
 
        am7xxx_device *new_device;
 

+       if (ctx == NULL) {
+               fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+               return NULL;
+       }
+
+       devices_list = &(ctx->devices_list);
+

        new_device = malloc(sizeof(*new_device));
        if (new_device == NULL) {
                perror("malloc");
        new_device = malloc(sizeof(*new_device));
        if (new_device == NULL) {
                perror("malloc");


@@ -332,6 +393,8 @@ static am7xxx_device *add_new_device(am7xxx_device **devices_list)
        }
        memset(new_device, 0, sizeof(*new_device));
 
        }
        memset(new_device, 0, sizeof(*new_device));
 

+       new_device->ctx = ctx;
+

        if (*devices_list == NULL) {
                *devices_list = new_device;
        } else {
        if (*devices_list == NULL) {
                *devices_list = new_device;
        } else {


@@ -343,12 +406,18 @@ static am7xxx_device *add_new_device(am7xxx_device **devices_list)
        return new_device;
 }
 
        return new_device;
 }
 

-static am7xxx_device *find_device(am7xxx_device *devices_list,
+static am7xxx_device *find_device(am7xxx_context *ctx,

                                  unsigned int device_index)
 {
        unsigned int i = 0;
                                  unsigned int device_index)
 {
        unsigned int i = 0;

-       am7xxx_device *current = devices_list;
+       am7xxx_device *current;

 
 

+       if (ctx == NULL) {
+               fprintf(stderr, "%s: context must not be NULL!\n", __func__);
+               return NULL;
+       }
+
+       current = ctx->devices_list;

        while (current && i++ < device_index)
                current = current->next;
 
        while (current && i++ < device_index)
                current = current->next;
 


@@ -420,7 +489,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                                        printf("am7xxx device found, index: %d, name: %s\n",
                                               current_index,
                                               supported_devices[j].name);
                                        printf("am7xxx device found, index: %d, name: %s\n",
                                               current_index,
                                               supported_devices[j].name);

-                                       new_device = add_new_device(&(ctx->devices_list));
+                                       new_device = add_new_device(ctx);

                                        if (new_device == NULL) {
                                                /* XXX, the caller may want
                                                 * to call am7xxx_shutdown() if
                                        if (new_device == NULL) {
                                                /* XXX, the caller may want
                                                 * to call am7xxx_shutdown() if


@@ -433,7 +502,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                                } else if (op == SCAN_OP_OPEN_DEVICE &&
                                           current_index == open_device_index) {
 
                                } else if (op == SCAN_OP_OPEN_DEVICE &&
                                           current_index == open_device_index) {
 

-                                       *dev = find_device(ctx->devices_list, open_device_index);
+                                       *dev = find_device(ctx, open_device_index);

                                        if (*dev == NULL) {
                                                ret = -ENODEV;
                                                goto out;
                                        if (*dev == NULL) {
                                                ret = -ENODEV;
                                                goto out;


@@ -464,6 +533,8 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                goto out;
        }
 
                goto out;
        }
 

+       /* everything went fine when building the device list */
+       ret = 0;

 out:
        libusb_free_device_list(list, 1);
        return ret;
 out:
        libusb_free_device_list(list, 1);
        return ret;


@@ -481,6 +552,9 @@ int am7xxx_init(am7xxx_context **ctx)
        }
        memset(*ctx, 0, sizeof(**ctx));
 
        }
        memset(*ctx, 0, sizeof(**ctx));
 

+       /* Set the highest log level during initialization */
+       (*ctx)->log_level = AM7XXX_LOG_TRACE;
+

        ret = libusb_init(&((*ctx)->usb_context));
        if (ret < 0)
                goto out_free_context;
        ret = libusb_init(&((*ctx)->usb_context));
        if (ret < 0)
                goto out_free_context;


@@ -494,6 +568,8 @@ int am7xxx_init(am7xxx_context **ctx)
                goto out;
        }
 
                goto out;
        }
 

+       /* Set a quieter log level as default for normal operation */
+       (*ctx)->log_level = AM7XXX_LOG_ERROR;

        return 0;
 
 out_free_context:
        return 0;
 
 out_free_context:


@@ -525,6 +601,11 @@ void am7xxx_shutdown(am7xxx_context *ctx)
        ctx = NULL;
 }
 
        ctx = NULL;
 }
 

+void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
+{
+       ctx->log_level = log_level;
+}
+

 int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
                       unsigned int device_index)
 {
 int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
                       unsigned int device_index)
 {