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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 02:57:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 02:57:58 +0000
commitbe1c7e50e1e8809ea56f2c9d472eccd8ffd73a97 (patch)
tree9754ff1ca740f6346cf8483ec915d4054bc5da2d /mqtt_websockets/c-rbuf/src
parentInitial commit. (diff)
downloadnetdata-be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97.tar.xz
netdata-be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97.zip
Adding upstream version 1.44.3.upstream/1.44.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mqtt_websockets/c-rbuf/src')
-rw-r--r--mqtt_websockets/c-rbuf/src/ringbuffer.c209
-rw-r--r--mqtt_websockets/c-rbuf/src/ringbuffer_internal.h43
2 files changed, 252 insertions, 0 deletions
diff --git a/mqtt_websockets/c-rbuf/src/ringbuffer.c b/mqtt_websockets/c-rbuf/src/ringbuffer.c
new file mode 100644
index 00000000..0dec1365
--- /dev/null
+++ b/mqtt_websockets/c-rbuf/src/ringbuffer.c
@@ -0,0 +1,209 @@
+/*
+ *
+ * Copyright: SPDX-License-Identifier: LGPL-3.0-only
+ *
+ * Author: Timotej Šiškovič <timotejs@gmail.com>
+ *
+ */
+
+#include "ringbuffer.h"
+#include "ringbuffer_internal.h"
+
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+
+#define MIN(a,b) (((a)<(b))?(a):(b))
+#define MAX(a,b) (((a)>(b))?(a):(b))
+
+// this allows user to use their own
+// custom memory allocation functions
+#ifdef RBUF_CUSTOM_MALLOC
+#include "ringbuffer_pal.h"
+#else
+#define crbuf_malloc(...) malloc(__VA_ARGS__)
+#define crbuf_free(...) free(__VA_ARGS__)
+#endif
+
+rbuf_t rbuf_create(size_t size)
+{
+ rbuf_t buffer = crbuf_malloc(sizeof(struct rbuf_t) + size);
+ if (!buffer)
+ return NULL;
+
+ memset(buffer, 0, sizeof(struct rbuf_t));
+
+ buffer->data = ((char*)buffer) + sizeof(struct rbuf_t);
+
+ buffer->head = buffer->data;
+ buffer->tail = buffer->data;
+ buffer->size = size;
+ buffer->end = buffer->data + size;
+
+ return buffer;
+}
+
+void rbuf_free(rbuf_t buffer)
+{
+ crbuf_free(buffer);
+}
+
+void rbuf_flush(rbuf_t buffer)
+{
+ buffer->head = buffer->data;
+ buffer->tail = buffer->data;
+ buffer->size_data = 0;
+}
+
+char *rbuf_get_linear_insert_range(rbuf_t buffer, size_t *bytes)
+{
+ *bytes = 0;
+ if (buffer->head == buffer->tail && buffer->size_data)
+ return NULL;
+
+ *bytes = ((buffer->head >= buffer->tail) ? buffer->end : buffer->tail) - buffer->head;
+ return buffer->head;
+}
+
+char *rbuf_get_linear_read_range(rbuf_t buffer, size_t *bytes)
+{
+ *bytes = 0;
+ if(buffer->head == buffer->tail && !buffer->size_data)
+ return NULL;
+
+ *bytes = ((buffer->tail >= buffer->head) ? buffer->end : buffer->head) - buffer->tail;
+
+ return buffer->tail;
+}
+
+int rbuf_bump_head(rbuf_t buffer, size_t bytes)
+{
+ size_t free_bytes = rbuf_bytes_free(buffer);
+ if (bytes > free_bytes)
+ return 0;
+ int i = buffer->head - buffer->data;
+ buffer->head = &buffer->data[(i + bytes) % buffer->size];
+ buffer->size_data += bytes;
+ return 1;
+}
+
+int rbuf_bump_tail(rbuf_t buffer, size_t bytes)
+{
+ if(!rbuf_bump_tail_noopt(buffer, bytes))
+ return 0;
+
+ // if tail catched up with head
+ // start writing buffer from beggining
+ // this is not necessary (rbuf must work well without it)
+ // but helps to optimize big writes as rbuf_get_linear_insert_range
+ // will return bigger continuous region
+ if(buffer->tail == buffer->head) {
+ assert(buffer->size_data == 0);
+ rbuf_flush(buffer);
+ }
+
+ return 1;
+}
+
+size_t rbuf_get_capacity(rbuf_t buffer)
+{
+ return buffer->size;
+}
+
+size_t rbuf_bytes_available(rbuf_t buffer)
+{
+ return buffer->size_data;
+}
+
+size_t rbuf_bytes_free(rbuf_t buffer)
+{
+ return buffer->size - buffer->size_data;
+}
+
+size_t rbuf_push(rbuf_t buffer, const char *data, size_t len)
+{
+ size_t to_cpy;
+ char *w_ptr = rbuf_get_linear_insert_range(buffer, &to_cpy);
+ if(!to_cpy)
+ return to_cpy;
+
+ to_cpy = MIN(to_cpy, len);
+ memcpy(w_ptr, data, to_cpy);
+ rbuf_bump_head(buffer, to_cpy);
+ if(to_cpy < len)
+ to_cpy += rbuf_push(buffer, &data[to_cpy], len - to_cpy);
+ return to_cpy;
+}
+
+size_t rbuf_pop(rbuf_t buffer, char *data, size_t len)
+{
+ size_t to_cpy;
+ const char *r_ptr = rbuf_get_linear_read_range(buffer, &to_cpy);
+ if(!to_cpy)
+ return to_cpy;
+
+ to_cpy = MIN(to_cpy, len);
+ memcpy(data, r_ptr, to_cpy);
+ rbuf_bump_tail(buffer, to_cpy);
+ if(to_cpy < len)
+ to_cpy += rbuf_pop(buffer, &data[to_cpy], len - to_cpy);
+ return to_cpy;
+}
+
+static inline void rbuf_ptr_inc(rbuf_t buffer, const char **ptr)
+{
+ (*ptr)++;
+ if(*ptr >= buffer->end)
+ *ptr = buffer->data;
+}
+
+int rbuf_memcmp(rbuf_t buffer, const char *haystack, const char *needle, size_t needle_bytes)
+{
+ const char *end = needle + needle_bytes;
+
+ // as head==tail can mean 2 things here
+ if (haystack == buffer->head && buffer->size_data) {
+ if (*haystack != *needle)
+ return (*haystack - *needle);
+ rbuf_ptr_inc(buffer, &haystack);
+ needle++;
+ }
+
+ while (haystack != buffer->head && needle != end) {
+ if (*haystack != *needle)
+ return (*haystack - *needle);
+ rbuf_ptr_inc(buffer, &haystack);
+ needle++;
+ }
+ return 0;
+}
+
+int rbuf_memcmp_n(rbuf_t buffer, const char *to_cmp, size_t to_cmp_bytes)
+{
+ return rbuf_memcmp(buffer, buffer->tail, to_cmp, to_cmp_bytes);
+}
+
+char *rbuf_find_bytes(rbuf_t buffer, const char *needle, size_t needle_bytes, int *found_idx)
+{
+ const char *ptr = buffer->tail;
+ *found_idx = 0;
+
+ if (!rbuf_bytes_available(buffer))
+ return NULL;
+
+ if (buffer->head == buffer->tail && buffer->size_data) {
+ if(!rbuf_memcmp(buffer, ptr, needle, needle_bytes))
+ return (char *)ptr;
+ rbuf_ptr_inc(buffer, &ptr);
+ (*found_idx)++;
+ }
+
+ while (ptr != buffer->head)
+ {
+ if(!rbuf_memcmp(buffer, ptr, needle, needle_bytes))
+ return (char *)ptr;
+ rbuf_ptr_inc(buffer, &ptr);
+ (*found_idx)++;
+ }
+ return NULL;
+}
diff --git a/mqtt_websockets/c-rbuf/src/ringbuffer_internal.h b/mqtt_websockets/c-rbuf/src/ringbuffer_internal.h
new file mode 100644
index 00000000..f7bdf815
--- /dev/null
+++ b/mqtt_websockets/c-rbuf/src/ringbuffer_internal.h
@@ -0,0 +1,43 @@
+/*
+ *
+ * Copyright: SPDX-License-Identifier: LGPL-3.0-only
+ *
+ * Author: Timotej Šiškovič <timotejs@gmail.com>
+ *
+ */
+
+#ifndef RINGBUFFER_INTERNAL_H
+#define RINGBUFFER_INTERNAL_H
+
+struct rbuf_t {
+ char *data;
+
+ // points to next byte where we can write
+ char *head;
+ // points to oldest (next to be poped) readable byte
+ char *tail;
+
+ // to avoid calculating data + size
+ // all the time
+ char *end;
+
+ size_t size;
+ size_t size_data;
+};
+
+/* this exists so that it can be tested by unit tests
+ * without optimization that resets head and tail to
+ * beginning if buffer empty
+ */
+inline static int rbuf_bump_tail_noopt(rbuf_t buffer, size_t bytes)
+{
+ if (bytes > buffer->size_data)
+ return 0;
+ int i = buffer->tail - buffer->data;
+ buffer->tail = &buffer->data[(i + bytes) % buffer->size];
+ buffer->size_data -= bytes;
+
+ return 1;
+}
+
+#endif