char: move ringbuf/memory to its own file

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 249 insertions, 0 deletions

diff --git a/chardev/char-ringbuf.c b/chardev/char-ringbuf.c
new file mode 100644
index 0000000000..d130069e88
--- /dev/null
+++ b/chardev/char-ringbuf.c
@@ -0,0 +1,249 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu/osdep.h"
+#include "sysemu/char.h"
+#include "qmp-commands.h"
+#include "qemu/base64.h"
+
+/* Ring buffer chardev */
+
+typedef struct {
+    Chardev parent;
+    size_t size;
+    size_t prod;
+    size_t cons;
+    uint8_t *cbuf;
+} RingBufChardev;
+
+#define RINGBUF_CHARDEV(obj)                                    \
+    OBJECT_CHECK(RingBufChardev, (obj), TYPE_CHARDEV_RINGBUF)
+
+static size_t ringbuf_count(const Chardev *chr)
+{
+    const RingBufChardev *d = RINGBUF_CHARDEV(chr);
+
+    return d->prod - d->cons;
+}
+
+static int ringbuf_chr_write(Chardev *chr, const uint8_t *buf, int len)
+{
+    RingBufChardev *d = RINGBUF_CHARDEV(chr);
+    int i;
+
+    if (!buf || (len < 0)) {
+        return -1;
+    }
+
+    for (i = 0; i < len; i++) {
+        d->cbuf[d->prod++ & (d->size - 1)] = buf[i];
+        if (d->prod - d->cons > d->size) {
+            d->cons = d->prod - d->size;
+        }
+    }
+
+    return len;
+}
+
+static int ringbuf_chr_read(Chardev *chr, uint8_t *buf, int len)
+{
+    RingBufChardev *d = RINGBUF_CHARDEV(chr);
+    int i;
+
+    qemu_mutex_lock(&chr->chr_write_lock);
+    for (i = 0; i < len && d->cons != d->prod; i++) {
+        buf[i] = d->cbuf[d->cons++ & (d->size - 1)];
+    }
+    qemu_mutex_unlock(&chr->chr_write_lock);
+
+    return i;
+}
+
+static void char_ringbuf_finalize(Object *obj)
+{
+    RingBufChardev *d = RINGBUF_CHARDEV(obj);
+
+    g_free(d->cbuf);
+}
+
+static void qemu_chr_open_ringbuf(Chardev *chr,
+                                  ChardevBackend *backend,
+                                  bool *be_opened,
+                                  Error **errp)
+{
+    ChardevRingbuf *opts = backend->u.ringbuf.data;
+    RingBufChardev *d = RINGBUF_CHARDEV(chr);
+
+    d->size = opts->has_size ? opts->size : 65536;
+
+    /* The size must be power of 2 */
+    if (d->size & (d->size - 1)) {
+        error_setg(errp, "size of ringbuf chardev must be power of two");
+        return;
+    }
+
+    d->prod = 0;
+    d->cons = 0;
+    d->cbuf = g_malloc0(d->size);
+}
+
+void qmp_ringbuf_write(const char *device, const char *data,
+                       bool has_format, enum DataFormat format,
+                       Error **errp)
+{
+    Chardev *chr;
+    const uint8_t *write_data;
+    int ret;
+    gsize write_count;
+
+    chr = qemu_chr_find(device);
+    if (!chr) {
+        error_setg(errp, "Device '%s' not found", device);
+        return;
+    }
+
+    if (!CHARDEV_IS_RINGBUF(chr)) {
+        error_setg(errp, "%s is not a ringbuf device", device);
+        return;
+    }
+
+    if (has_format && (format == DATA_FORMAT_BASE64)) {
+        write_data = qbase64_decode(data, -1,
+                                    &write_count,
+                                    errp);
+        if (!write_data) {
+            return;
+        }
+    } else {
+        write_data = (uint8_t *)data;
+        write_count = strlen(data);
+    }
+
+    ret = ringbuf_chr_write(chr, write_data, write_count);
+
+    if (write_data != (uint8_t *)data) {
+        g_free((void *)write_data);
+    }
+
+    if (ret < 0) {
+        error_setg(errp, "Failed to write to device %s", device);
+        return;
+    }
+}
+
+char *qmp_ringbuf_read(const char *device, int64_t size,
+                       bool has_format, enum DataFormat format,
+                       Error **errp)
+{
+    Chardev *chr;
+    uint8_t *read_data;
+    size_t count;
+    char *data;
+
+    chr = qemu_chr_find(device);
+    if (!chr) {
+        error_setg(errp, "Device '%s' not found", device);
+        return NULL;
+    }
+
+    if (!CHARDEV_IS_RINGBUF(chr)) {
+        error_setg(errp, "%s is not a ringbuf device", device);
+        return NULL;
+    }
+
+    if (size <= 0) {
+        error_setg(errp, "size must be greater than zero");
+        return NULL;
+    }
+
+    count = ringbuf_count(chr);
+    size = size > count ? count : size;
+    read_data = g_malloc(size + 1);
+
+    ringbuf_chr_read(chr, read_data, size);
+
+    if (has_format && (format == DATA_FORMAT_BASE64)) {
+        data = g_base64_encode(read_data, size);
+        g_free(read_data);
+    } else {
+        /*
+         * FIXME should read only complete, valid UTF-8 characters up
+         * to @size bytes.  Invalid sequences should be replaced by a
+         * suitable replacement character.  Except when (and only
+         * when) ring buffer lost characters since last read, initial
+         * continuation characters should be dropped.
+         */
+        read_data[size] = 0;
+        data = (char *)read_data;
+    }
+
+    return data;
+}
+
+static void qemu_chr_parse_ringbuf(QemuOpts *opts, ChardevBackend *backend,
+                                   Error **errp)
+{
+    int val;
+    ChardevRingbuf *ringbuf;
+
+    backend->type = CHARDEV_BACKEND_KIND_RINGBUF;
+    ringbuf = backend->u.ringbuf.data = g_new0(ChardevRingbuf, 1);
+    qemu_chr_parse_common(opts, qapi_ChardevRingbuf_base(ringbuf));
+
+    val = qemu_opt_get_size(opts, "size", 0);
+    if (val != 0) {
+        ringbuf->has_size = true;
+        ringbuf->size = val;
+    }
+}
+
+static void char_ringbuf_class_init(ObjectClass *oc, void *data)
+{
+    ChardevClass *cc = CHARDEV_CLASS(oc);
+
+    cc->parse = qemu_chr_parse_ringbuf;
+    cc->open = qemu_chr_open_ringbuf;
+    cc->chr_write = ringbuf_chr_write;
+}
+
+static const TypeInfo char_ringbuf_type_info = {
+    .name = TYPE_CHARDEV_RINGBUF,
+    .parent = TYPE_CHARDEV,
+    .class_init = char_ringbuf_class_init,
+    .instance_size = sizeof(RingBufChardev),
+    .instance_finalize = char_ringbuf_finalize,
+};
+
+/* Bug-compatibility: */
+static const TypeInfo char_memory_type_info = {
+    .name = TYPE_CHARDEV_MEMORY,
+    .parent = TYPE_CHARDEV_RINGBUF,
+};
+
+static void register_types(void)
+{
+    type_register_static(&char_ringbuf_type_info);
+    type_register_static(&char_memory_type_info);
+}
+
+type_init(register_types);