1 files changed, 127 insertions, 0 deletions
diff --git a/mqtt_websockets/src/mqtt_wss_log.c b/mqtt_websockets/src/mqtt_wss_log.c
new file mode 100644
index 00000000..2c8cf32e
--- /dev/null
+++ b/mqtt_websockets/src/mqtt_wss_log.c
@@ -0,0 +1,127 @@
+#include "mqtt_wss_log.h"
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include "common_internal.h"
+
+struct mqtt_wss_log_ctx {
+    mqtt_wss_log_callback_t extern_log_fnc;
+    char *ctx_prefix;
+    char *buffer;
+    char *buffer_w_ptr;
+    size_t buffer_bytes_avail;
+};
+
+#define LOG_BUFFER_SIZE 1024 * 4
+#define LOG_CTX_PREFIX_SEV_STR "  : "
+#define LOG_CTX_PREFIX_LIMIT 15
+#define LOG_CTX_PREFIX_LIMIT_STR (LOG_CTX_PREFIX_LIMIT - (2 + strlen(LOG_CTX_PREFIX_SEV_STR)))  // with [] characters and affixed ' ' it is total 15 chars
+#if (LOG_CTX_PREFIX_LIMIT * 10) > LOG_BUFFER_SIZE
+#error "LOG_BUFFER_SIZE too small"
+#endif
+mqtt_wss_log_ctx_t mqtt_wss_log_ctx_create(const char *ctx_prefix, mqtt_wss_log_callback_t log_callback)
+{
+    mqtt_wss_log_ctx_t ctx = mw_calloc(1, sizeof(struct mqtt_wss_log_ctx));
+    if(!ctx)
+        return NULL;
+
+    if(log_callback) {
+        ctx->extern_log_fnc = log_callback;
+        ctx->buffer = mw_calloc(1, LOG_BUFFER_SIZE);
+        if(!ctx->buffer)
+            goto cleanup;
+
+        ctx->buffer_w_ptr = ctx->buffer;
+        if(ctx_prefix) {
+            *(ctx->buffer_w_ptr++) = '[';
+            strncpy(ctx->buffer_w_ptr, ctx_prefix, LOG_CTX_PREFIX_LIMIT_STR);
+            ctx->buffer_w_ptr += strnlen(ctx_prefix, LOG_CTX_PREFIX_LIMIT_STR);
+            *(ctx->buffer_w_ptr++) = ']';
+        }
+        strcpy(ctx->buffer_w_ptr, LOG_CTX_PREFIX_SEV_STR);
+        ctx->buffer_w_ptr += strlen(LOG_CTX_PREFIX_SEV_STR);
+        // no term '\0' -> calloc is used
+
+        ctx->buffer_bytes_avail = LOG_BUFFER_SIZE - strlen(ctx->buffer);
+
+        return ctx;
+    }
+
+    if(ctx_prefix) {
+        ctx->ctx_prefix = strndup(ctx_prefix, LOG_CTX_PREFIX_LIMIT_STR);
+        if(!ctx->ctx_prefix)
+            goto cleanup;
+    }
+
+    return ctx;
+
+cleanup:
+    mw_free(ctx);
+    return NULL;
+}
+
+void mqtt_wss_log_ctx_destroy(mqtt_wss_log_ctx_t ctx)
+{
+    mw_free(ctx->ctx_prefix);
+    mw_free(ctx->buffer);
+    mw_free(ctx);
+}
+
+static inline char severity_to_c(int severity)
+{
+    switch (severity) {
+        case MQTT_WSS_LOG_FATAL:
+            return 'F';
+        case MQTT_WSS_LOG_ERROR:
+            return 'E';
+        case MQTT_WSS_LOG_WARN:
+            return 'W';
+        case MQTT_WSS_LOG_INFO:
+            return 'I';
+        case MQTT_WSS_LOG_DEBUG:
+            return 'D';
+        default:
+            return '?';
+    }
+}
+
+void mws_log(int severity, mqtt_wss_log_ctx_t ctx, const char *fmt, va_list args)
+{
+    size_t size;
+
+    if(ctx->extern_log_fnc) {
+        size = vsnprintf(ctx->buffer_w_ptr, ctx->buffer_bytes_avail, fmt, args);
+        *(ctx->buffer_w_ptr - 3) = severity_to_c(severity);
+
+        ctx->extern_log_fnc(severity, ctx->buffer);
+
+        if(size >= ctx->buffer_bytes_avail)
+            mws_error(ctx, "Last message of this type was truncated! Consider what you log or increase LOG_BUFFER_SIZE if really needed.");
+
+        return;
+    }
+
+    if(ctx->ctx_prefix)
+        printf("[%s] ", ctx->ctx_prefix);
+
+    printf("%c: ", severity_to_c(severity));
+
+    vprintf(fmt, args);
+    putchar('\n');
+}
+
+#define DEFINE_MWS_SEV_FNC(severity_fncname, severity) \
+void mws_ ## severity_fncname(mqtt_wss_log_ctx_t ctx, const char *fmt, ...) \
+{ \
+    va_list args; \
+    va_start(args, fmt); \
+    mws_log(severity, ctx, fmt, args); \
+    va_end(args); \
+}
+
+DEFINE_MWS_SEV_FNC(fatal, MQTT_WSS_LOG_FATAL)
+DEFINE_MWS_SEV_FNC(error, MQTT_WSS_LOG_ERROR)
+DEFINE_MWS_SEV_FNC(warn,  MQTT_WSS_LOG_WARN )
+DEFINE_MWS_SEV_FNC(info,  MQTT_WSS_LOG_INFO )
+DEFINE_MWS_SEV_FNC(debug, MQTT_WSS_LOG_DEBUG)