1 files changed, 177 insertions, 0 deletions

diff --git a/utils/jztool/src/context.c b/utils/jztool/src/context.c
new file mode 100644
index 0000000000..d269d1eece
--- /dev/null
+++ b/utils/jztool/src/context.c
@@ -0,0 +1,177 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2021 Aidan MacDonald
+ *
+ * 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
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "jztool_private.h"
+#include <string.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <time.h>
+
+#ifdef WIN32
+# include <windows.h>
+#endif
+
+/** \brief Allocate a library context
+ * \returns New context or NULL if out of memory
+ */
+jz_context* jz_context_create(void)
+{
+    jz_context* jz = malloc(sizeof(struct jz_context));
+    if(!jz)
+        return NULL;
+
+    memset(jz, 0, sizeof(struct jz_context));
+    jz->log_level = JZ_LOG_ERROR;
+    return jz;
+}
+
+/** \brief Destroy the context and free its memory */
+void jz_context_destroy(jz_context* jz)
+{
+    if(jz->usb_ctx) {
+        jz_log(jz, JZ_LOG_ERROR, "BUG: USB was not cleaned up properly");
+        libusb_exit(jz->usb_ctx);
+    }
+
+    free(jz);
+}
+
+/** \brief Set a user data pointer. Useful for callbacks. */
+void jz_context_set_user_data(jz_context* jz, void* ptr)
+{
+    jz->user_data = ptr;
+}
+
+/** \brief Get the user data pointer */
+void* jz_context_get_user_data(jz_context* jz)
+{
+    return jz->user_data;
+}
+
+/** \brief Set the log message callback.
+ * \note By default, no message callback is set! No messages will be logged
+ *       in this case, so ensure you set a callback if messages are desired.
+ */
+void jz_context_set_log_cb(jz_context* jz, jz_log_cb cb)
+{
+    jz->log_cb = cb;
+}
+
+/** \brief Set the log level.
+ *
+ * Messages of less importance than the set log level are not logged.
+ * The default log level is `JZ_LOG_WARNING`. The special log level
+ * `JZ_LOG_IGNORE` can be used to disable all logging temporarily.
+ *
+ * The `JZ_LOG_DEBUG` log level is extremely verbose and will log all calls,
+ * normally it's only useful for catching bugs.
+ */
+void jz_context_set_log_level(jz_context* jz, jz_log_level lev)
+{
+    jz->log_level = lev;
+}
+
+/** \brief Log an informational message.
+ * \param lev   Log level for this message
+ * \param fmt   `printf` style message format string
+ */
+void jz_log(jz_context* jz, jz_log_level lev, const char* fmt, ...)
+{
+    if(!jz->log_cb)
+        return;
+    if(lev == JZ_LOG_IGNORE)
+        return;
+    if(lev > jz->log_level)
+        return;
+
+    va_list ap;
+
+    va_start(ap, fmt);
+    int n = vsnprintf(NULL, 0, fmt, ap);
+    va_end(ap);
+
+    if(n < 0)
+        return;
+
+    char* buf = malloc(n + 1);
+    if(!buf)
+        return;
+
+    va_start(ap, fmt);
+    n = vsnprintf(buf, n + 1, fmt, ap);
+    va_end(ap);
+
+    if(n >= 0)
+        jz->log_cb(lev, buf);
+
+    free(buf);
+}
+
+/** \brief Log callback which writes messages to `stderr`.
+ */
+void jz_log_cb_stderr(jz_log_level lev, const char* msg)
+{
+    static const char* const tags[] =
+        {"ERROR", "WARNING", "NOTICE", "DETAIL", "DEBUG"};
+    fprintf(stderr, "[%7s] %s\n", tags[lev], msg);
+    fflush(stderr);
+}
+
+/** \brief Sleep for `ms` milliseconds.
+ */
+void jz_sleepms(int ms)
+{
+#ifdef WIN32
+    Sleep(ms);
+#else
+    struct timespec ts;
+    long ns = ms % 1000;
+    ts.tv_nsec = ns * 1000 * 1000;
+    ts.tv_sec = ms / 1000;
+    nanosleep(&ts, NULL);
+#endif
+}
+
+/** \brief Add reference to libusb context, allocating it if necessary */
+int jz_context_ref_libusb(jz_context* jz)
+{
+    if(jz->usb_ctxref == 0) {
+        int rc = libusb_init(&jz->usb_ctx);
+        if(rc < 0) {
+            jz_log(jz, JZ_LOG_ERROR, "libusb_init: %s", libusb_strerror(rc));
+            return JZ_ERR_USB;
+        }
+    }
+
+    jz->usb_ctxref += 1;
+    return JZ_SUCCESS;
+}
+
+/** \brief Remove reference to libusb context, freeing if it hits zero */
+void jz_context_unref_libusb(jz_context* jz)
+{
+    if(--jz->usb_ctxref == 0) {
+        libusb_exit(jz->usb_ctx);
+        jz->usb_ctx = NULL;
+    }
+}