MINOR: quic: Add a ring buffer implementation for QUIC
This implementation is inspired from Linux kernel circular buffer implementation
(see include/linux/circ-buf.h). Such buffers may be used at the same time both
by writer and reader (lock-free).
diff --git a/Makefile b/Makefile
index 0cb1541..e586ba4 100644
--- a/Makefile
+++ b/Makefile
@@ -590,7 +590,7 @@
ifneq ($(USE_QUIC),)
OPTIONS_OBJS += src/quic_sock.o src/proto_quic.o src/xprt_quic.o src/quic_tls.o \
src/quic_frame.o src/quic_cc.o src/quic_cc_newreno.o src/mux_quic.o \
- src/qpack-dec.o src/qpack-tbl.o src/h3.o
+ src/cbuf.o src/qpack-dec.o src/qpack-tbl.o src/h3.o
endif
ifneq ($(USE_LUA),)
diff --git a/include/haproxy/cbuf-t.h b/include/haproxy/cbuf-t.h
new file mode 100644
index 0000000..876c804
--- /dev/null
+++ b/include/haproxy/cbuf-t.h
@@ -0,0 +1,46 @@
+/*
+ * include/haprox/cbuf-t.h
+ * This file contains definition for circular buffers.
+ *
+ * Copyright 2021 HAProxy Technologies, Frédéric Lécaille <flecaille@haproxy.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _HAPROXY_CBUF_T_H
+#define _HAPROXY_CBUF_T_H
+#ifdef USE_QUIC
+#ifndef USE_OPENSSL
+#error "Must define USE_OPENSSL"
+#endif
+#endif
+
+#include <haproxy/list-t.h>
+
+/* QUIC circular buffer internal buffer size (must be a power of 2) */
+#define CBUF_BUFSZ (1UL << 11)
+
+extern struct pool_head *pool_head_cbuf;
+
+struct cbuf {
+ /* buffer */
+ unsigned char buf[CBUF_BUFSZ];
+ /* Writer index */
+ int wr;
+ /* Reader index */
+ int rd;
+};
+
+#endif /* _HAPROXY_CBUF_T_H */
diff --git a/include/haproxy/cbuf.h b/include/haproxy/cbuf.h
new file mode 100644
index 0000000..2b0ea65
--- /dev/null
+++ b/include/haproxy/cbuf.h
@@ -0,0 +1,138 @@
+/*
+ * include/haprox/cbuf.h
+ * This file contains definitions and prototypes for circular buffers.
+ * Inspired from Linux circular buffers (include/linux/circ_buf.h).
+ *
+ * Copyright 2021 HAProxy Technologies, Frédéric Lécaille <flecaille@haproxy.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _HAPROXY_CBUF_H
+#define _HAPROXY_CBUF_H
+#ifdef USE_QUIC
+#ifndef USE_OPENSSL
+#error "Must define USE_OPENSSL"
+#endif
+#endif
+
+#include <haproxy/atomic.h>
+#include <haproxy/list.h>
+#include <haproxy/cbuf-t.h>
+
+struct cbuf *cbuf_new(void);
+void cbuf_free(struct cbuf *cbuf);
+
+/* Amount of data between <rd> and <wr> */
+#define CBUF_DATA(wr, rd, size) (((wr) - (rd)) & ((size) - 1))
+
+/* Return the writer position in <cbuf>.
+ * To be used only by the writer!
+ */
+static inline unsigned char *cb_wr(struct cbuf *cbuf)
+{
+ return cbuf->buf + cbuf->wr;
+}
+
+/* Reset the reader index.
+ * To be used by a reader!
+ */
+static inline void cb_rd_reset(struct cbuf *cbuf)
+{
+ cbuf->rd = 0;
+}
+
+/* Reset the writer index.
+ * To be used by a writer!
+ */
+static inline void cb_wr_reset(struct cbuf *cbuf)
+{
+ cbuf->wr = 0;
+}
+
+/* Increase <cbuf> circular buffer data by <count>.
+ * To be used by a writer!
+ */
+static inline void cb_add(struct cbuf *cbuf, size_t count)
+{
+ cbuf->wr = (cbuf->wr + count) & (CBUF_BUFSZ - 1);
+}
+
+/* Return the reader position in <cbuf>.
+ * To be used only by the reader!
+ */
+static inline unsigned char *cb_rd(struct cbuf *cbuf)
+{
+ return cbuf->buf + cbuf->rd;
+}
+
+/* Skip <count> byte in <cbuf> circular buffer.
+ * To be used by a reader!
+ */
+static inline void cb_del(struct cbuf *cbuf, size_t count)
+{
+ cbuf->rd = (cbuf->rd + count) & (CBUF_BUFSZ - 1);
+}
+
+/* Return the amount of data left in <cbuf>.
+ * To be used only by the writer!
+ */
+static inline int cb_data(struct cbuf *cbuf)
+{
+ int rd;
+
+ rd = HA_ATOMIC_LOAD(&cbuf->rd);
+ return CBUF_DATA(cbuf->wr, rd, CBUF_BUFSZ);
+}
+
+/* Return the amount of room left in <cbuf> minus 1 to distinguish
+ * the case where the buffer is full from the case where is is empty
+ * To be used only by the write!
+ */
+static inline int cb_room(struct cbuf *cbuf)
+{
+ int rd;
+
+ rd = HA_ATOMIC_LOAD(&cbuf->rd);
+ return CBUF_DATA(rd, cbuf->wr + 1, CBUF_BUFSZ);
+}
+
+/* Return the amount of contiguous data left in <cbuf>.
+ * To be used only by the reader!
+ */
+static inline int cb_contig_data(struct cbuf *cbuf)
+{
+ int end, n;
+
+ end = CBUF_BUFSZ - cbuf->rd;
+ n = (HA_ATOMIC_LOAD(&cbuf->wr) + end) & (CBUF_BUFSZ - 1);
+
+ return n < end ? n : end;
+}
+
+/* Return the amount of contiguous space left in <cbuf>.
+ * To be used only by the writer!
+ */
+static inline int cb_contig_space(struct cbuf *cbuf)
+{
+ int end, n;
+
+ end = CBUF_BUFSZ - 1 - cbuf->wr;
+ n = (HA_ATOMIC_LOAD(&cbuf->rd) + end) & (CBUF_BUFSZ - 1);
+
+ return n <= end ? n : end + 1;
+}
+
+#endif /* _HAPROXY_CBUF_H */
diff --git a/src/cbuf.c b/src/cbuf.c
new file mode 100644
index 0000000..d58ff97
--- /dev/null
+++ b/src/cbuf.c
@@ -0,0 +1,55 @@
+/*
+ * Circular buffer management
+ *
+ * Copyright 2021 HAProxy Technologies, Frédéric Lécaille <flecaill@haproxy.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <haproxy/list.h>
+#include <haproxy/pool.h>
+#include <haproxy/cbuf-t.h>
+
+DECLARE_POOL(pool_head_cbuf, "cbuf_pool", sizeof(struct cbuf));
+
+/* Allocate and return a new circular buffer if succeeded, NULL if not. */
+struct cbuf *cbuf_new(void)
+{
+ struct cbuf *cbuf;
+
+ cbuf = pool_alloc(pool_head_cbuf);
+ if (cbuf) {
+ cbuf->wr = 0;
+ cbuf->rd = 0;
+ }
+
+ return cbuf;
+}
+
+/* Free QUIC ring <cbuf> */
+void cbuf_free(struct cbuf *cbuf)
+{
+ if (!cbuf)
+ return;
+
+ pool_free(pool_head_cbuf, cbuf);
+}
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ */