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authorRichard Braun <rbraun@sceen.net>2018-08-31 01:15:43 +0200
committerRichard Braun <rbraun@sceen.net>2018-08-31 01:15:43 +0200
commitb0969d077818a74f2fd26b5a7bec2263a4517b07 (patch)
tree67ba719aeb48682db21274e19e0d9c3ef7a547b8
parent863bc0bbb53e27178a041aad563ecc96e5f076ce (diff)
mbuf: new module
-rw-r--r--Makefile.am6
-rw-r--r--src/mbuf.c165
-rw-r--r--src/mbuf.h87
-rw-r--r--test/test_mbuf.c222
4 files changed, 480 insertions, 0 deletions
diff --git a/Makefile.am b/Makefile.am
index aca192c..345d1fa 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -34,6 +34,8 @@ librbraun_la_SOURCES = \
src/list.c \
src/list.h \
src/macros.h \
+ src/mbuf.c \
+ src/mbuf.h \
src/plist.c \
src/plist.h \
src/rbtree.c \
@@ -54,6 +56,7 @@ bin_PROGRAMS = \
test_fmt_sprintf \
test_fmt_sscanf \
test_hlist \
+ test_mbuf \
test_plist \
test_rbtree \
test_rdxtree \
@@ -75,6 +78,9 @@ test_fmt_sscanf_LDADD = librbraun.la
test_hlist_SOURCES = test/test_hlist.c
test_hlist_LDADD = librbraun.la
+test_mbuf_SOURCES = test/test_mbuf.c
+test_mbuf_LDADD = librbraun.la
+
test_plist_SOURCES = test/test_plist.c
test_plist_LDADD = librbraun.la
diff --git a/src/mbuf.c b/src/mbuf.c
new file mode 100644
index 0000000..27d6221
--- /dev/null
+++ b/src/mbuf.c
@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2018 Richard Braun.
+ *
+ * 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.
+ *
+ * Upstream site with license notes :
+ * http://git.sceen.net/rbraun/librbraun.git/
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include "mbuf.h"
+
+/*
+ * Message header.
+ *
+ * The size denotes the size of the data, without the header.
+ */
+struct mbuf_hdr {
+ uint32_t size;
+ char data[];
+};
+
+static int
+mbuf_hdr_init(struct mbuf_hdr *hdr, size_t size)
+{
+ hdr->size = size;
+
+ if (hdr->size != size) {
+ return EMSGSIZE;
+ }
+
+ return 0;
+}
+
+static size_t
+mbuf_hdr_total_size(const struct mbuf_hdr *hdr)
+{
+ return sizeof(*hdr) + hdr->size;
+}
+
+static size_t
+mbuf_hdr_msg_size(const struct mbuf_hdr *hdr)
+{
+ return hdr->size;
+}
+
+void
+mbuf_init(struct mbuf *mbuf, void *buf, size_t capacity)
+{
+ cbuf_init(&mbuf->cbuf, buf, capacity);
+}
+
+void
+mbuf_clear(struct mbuf *mbuf)
+{
+ return cbuf_clear(&mbuf->cbuf);
+}
+
+static void
+mbuf_clear_old_msgs(struct mbuf *mbuf, size_t total_size)
+{
+ struct mbuf_hdr hdr;
+ size_t size;
+ int error;
+
+ do {
+ size = sizeof(hdr);
+ error = cbuf_pop(&mbuf->cbuf, &hdr, &size);
+ assert(!error);
+
+ if (size == 0) {
+ break;
+ }
+
+ size = mbuf_hdr_msg_size(&hdr);
+ error = cbuf_pop(&mbuf->cbuf, NULL, &size);
+ assert(!error && (size == mbuf_hdr_msg_size(&hdr)));
+ } while (cbuf_avail_size(&mbuf->cbuf) < total_size);
+}
+
+int
+mbuf_push(struct mbuf *mbuf, const void *buf, size_t size, bool erase)
+{
+ struct mbuf_hdr hdr;
+ size_t total_size;
+ int error;
+
+ error = mbuf_hdr_init(&hdr, size);
+
+ if (error) {
+ return error;
+ }
+
+ total_size = mbuf_hdr_total_size(&hdr);
+
+ if (total_size > cbuf_avail_size(&mbuf->cbuf)) {
+ if (!erase || (total_size > cbuf_capacity(&mbuf->cbuf))) {
+ return EMSGSIZE;
+ }
+
+ mbuf_clear_old_msgs(mbuf, total_size);
+ }
+
+ error = cbuf_push(&mbuf->cbuf, &hdr, sizeof(hdr), erase);
+ assert(!error);
+ error = cbuf_push(&mbuf->cbuf, buf, size, erase);
+ assert(!error);
+
+ return 0;
+}
+
+int
+mbuf_pop(struct mbuf *mbuf, void *buf, size_t *sizep)
+{
+ struct mbuf_hdr hdr;
+ size_t start, size;
+ int error;
+
+ start = cbuf_start(&mbuf->cbuf);
+
+ size = sizeof(hdr);
+ error = cbuf_read(&mbuf->cbuf, start, &hdr, &size);
+ assert(!error);
+
+ if (size == 0) {
+ return EAGAIN;
+ }
+
+ assert(size == sizeof(hdr));
+ size = mbuf_hdr_msg_size(&hdr);
+
+ if (size > *sizep) {
+ error = EMSGSIZE;
+ goto out;
+ }
+
+ cbuf_set_start(&mbuf->cbuf, start + sizeof(hdr));
+ error = cbuf_pop(&mbuf->cbuf, buf, &size);
+ assert(!error && (size == mbuf_hdr_msg_size(&hdr)));
+
+out:
+ *sizep = size;
+ return error;
+}
diff --git a/src/mbuf.h b/src/mbuf.h
new file mode 100644
index 0000000..f1464c7
--- /dev/null
+++ b/src/mbuf.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2018 Richard Braun.
+ *
+ * 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.
+ *
+ * Upstream site with license notes :
+ * http://git.sceen.net/rbraun/librbraun.git/
+ *
+ *
+ * FIFO message buffer.
+ */
+
+#ifndef MBUF_H
+#define MBUF_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#include "cbuf.h"
+
+/*
+ * Message buffer.
+ *
+ * Message buffers are built on top of circular byte buffers. They provide
+ * discrete message transfer from a producer to a consumer.
+ */
+struct mbuf {
+ struct cbuf cbuf;
+};
+
+/*
+ * Initialize a message buffer.
+ *
+ * The descriptor is set to use the given buffer for storage. Capacity
+ * must be a power-of-two.
+ */
+void mbuf_init(struct mbuf *mbuf, void *buf, size_t capacity);
+
+/*
+ * Clear a message buffer.
+ */
+void mbuf_clear(struct mbuf *mbuf);
+
+/*
+ * Push a message to a message buffer.
+ *
+ * If the message doesn't fit in the message buffer, either because it is
+ * larger than the capacity, or because the function isn't allowed to erase
+ * old messages and the message buffer doesn't have enough available memory
+ * for the new message, EMSGSIZE is returned.
+ */
+int mbuf_push(struct mbuf *mbuf, const void *buf, size_t size, bool erase);
+
+/*
+ * Pop a message from a message buffer.
+ *
+ * On entry, the sizep argument points to the size of the output buffer.
+ * On return, it is updated to the size of the message. If the message
+ * doesn't fit in the output buffer, it is not popped, EMSGSIZE is
+ * returned, but the sizep argument is updated nonetheless to let the
+ * user know the message size, to potentially retry with a larger buffer.
+ *
+ * If the buffer is empty, EAGAIN is returned, and the size of the output
+ * buffer is unmodified.
+ *
+ * The output buffer may be NULL, in which case this function acts as if
+ * it wasn't, but without writing output data.
+ */
+int mbuf_pop(struct mbuf *mbuf, void *buf, size_t *sizep);
+
+#endif /* MBUF_H */
diff --git a/test/test_mbuf.c b/test/test_mbuf.c
new file mode 100644
index 0000000..6b3f90f
--- /dev/null
+++ b/test/test_mbuf.c
@@ -0,0 +1,222 @@
+/*
+ * Copyright (c) 2018 Richard Braun.
+ *
+ * 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 <errno.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <check.h>
+#include <macros.h>
+#include <mbuf.h>
+
+static void
+test_regular(void)
+{
+ char mbuf_buf[32], buffer[8];
+ struct mbuf mbuf;
+ size_t size;
+ int error;
+
+ mbuf_init(&mbuf, mbuf_buf, sizeof(mbuf_buf));
+
+#define STRING "abcdef"
+ error = mbuf_push(&mbuf, STRING, STRLEN(STRING) + 1, false);
+ check(!error);
+#undef STRING
+
+#define STRING "xyz"
+ error = mbuf_push(&mbuf, STRING, STRLEN(STRING) + 1, false);
+ check(!error);
+#undef STRING
+
+#define STRING "abcdef"
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(!error);
+ check(size == (STRLEN(STRING) + 1));
+#undef STRING
+
+#define STRING "xyz"
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(!error);
+ check(size == (STRLEN(STRING) + 1));
+#undef STRING
+
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(error == EAGAIN);
+}
+
+static void
+test_write_full(void)
+{
+ char mbuf_buf[16], buffer[8];
+ struct mbuf mbuf;
+ size_t size;
+ int error;
+
+ mbuf_init(&mbuf, mbuf_buf, sizeof(mbuf_buf));
+
+#define STRING "abcdef"
+ error = mbuf_push(&mbuf, STRING, STRLEN(STRING) + 1, false);
+ check(!error);
+#undef STRING
+
+#define STRING "xyz"
+ error = mbuf_push(&mbuf, STRING, STRLEN(STRING) + 1, false);
+ check(error == EMSGSIZE);
+#undef STRING
+
+#define STRING "abcdef"
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(!error);
+ check(size == (STRLEN(STRING) + 1));
+#undef STRING
+
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(error == EAGAIN);
+}
+
+static void
+test_overwrite(void)
+{
+ char mbuf_buf[16], buffer[8];
+ struct mbuf mbuf;
+ size_t size;
+ int error;
+
+ mbuf_init(&mbuf, mbuf_buf, sizeof(mbuf_buf));
+
+#define STRING "abcdef"
+ error = mbuf_push(&mbuf, STRING, STRLEN(STRING) + 1, true);
+ check(!error);
+#undef STRING
+
+#define STRING "xyz"
+ error = mbuf_push(&mbuf, STRING, STRLEN(STRING) + 1, true);
+ check(!error);
+#undef STRING
+
+#define STRING "xyz"
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(!error);
+ check(size == (STRLEN(STRING) + 1));
+#undef STRING
+
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(error == EAGAIN);
+}
+
+static void
+test_msg_too_big(void)
+{
+ char mbuf_buf[8], buffer[8];
+ struct mbuf mbuf;
+ size_t size;
+ int error;
+
+ mbuf_init(&mbuf, mbuf_buf, sizeof(mbuf_buf));
+
+#define STRING "abcdef"
+ error = mbuf_push(&mbuf, STRING, STRLEN(STRING) + 1, true);
+ check(error == EMSGSIZE);
+#undef STRING
+
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(error == EAGAIN);
+}
+
+static void
+test_msg_far_too_big(void)
+{
+ char mbuf_buf[8], buffer[8];
+ struct mbuf mbuf;
+ size_t size;
+ int error;
+
+ if (sizeof(size_t) <= sizeof(uint32_t)) {
+ fprintf(stderr, "warning: %s disabled\n", __func__);
+ return;
+ }
+
+ mbuf_init(&mbuf, mbuf_buf, (size_t)1 << 36);
+
+#define STRING "abcdef"
+ size = (size_t)1 << 32;
+ error = mbuf_push(&mbuf, STRING, size, true);
+ check(error == EMSGSIZE);
+#undef STRING
+
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(error == EAGAIN);
+}
+
+static void
+test_peak(void)
+{
+ char mbuf_buf[16], buffer[8];
+ struct mbuf mbuf;
+ size_t size;
+ int error;
+
+ mbuf_init(&mbuf, mbuf_buf, sizeof(mbuf_buf));
+
+#define STRING "abcdef"
+ error = mbuf_push(&mbuf, STRING, STRLEN(STRING) + 1, true);
+ check(!error);
+#undef STRING
+
+#define STRING "abcdef"
+ size = 0;
+ error = mbuf_pop(&mbuf, NULL, &size);
+ check((error == EMSGSIZE) && (size == (STRLEN(STRING) + 1)));
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(!error && (size == (STRLEN(STRING) + 1)));
+#undef STRING
+
+ size = sizeof(buffer);
+ error = mbuf_pop(&mbuf, buffer, &size);
+ check(error == EAGAIN);
+}
+
+int
+main(void)
+{
+ test_regular();
+ test_write_full();
+ test_overwrite();
+ test_msg_too_big();
+ test_msg_far_too_big();
+ test_peak();
+
+ return EXIT_SUCCESS;
+}