nbuf: add buffer type and utilities

include/neo.h

@@ -11,6 +11,7 @@ extern "C" {
 #endif
 
 #include "neo/_error.h"
+#include "neo/_nbuf.h"
 #include "neo/_nref.h"
 #include "neo/_types.h"
 #include "neo/_stddef.h"

include/neo/_nbuf.h

@@ -0,0 +1,100 @@
+/** See the end of this file for copyright and license terms. */
+
+#pragma once
+
+#include "neo/_toolchain.h"
+#include "neo/_types.h"
+
+/**
+ * Create a new buffer of fixed size.
+ *
+ * If allocation fails or `size` is 0, an error is yeeted.
+ *
+ * @param size: Size in bytes
+ * @param err: Error pointer
+ * @returns The buffer, except if an error occurred
+ */
+nbuf_t *nbuf_create(usize size, error *err);
+
+/**
+ * Create a new buffer of fixed size and copy `data` into it.
+ *
+ * The original pointer is neither modified nor deallocated.
+ * If allocation fails, `data` is `nil`, or `size` is 0, an error is yeeted.
+ *
+ * @param data: Raw data to fill the buffer with
+ * @param size: How many bytes are read from `data`, and the buffer size
+ * @param err: Error pointer
+ * @returns The buffer, except if an error occurred
+ */
+nbuf_t *nbuf_from(const void *restrict data, usize size, error *err);
+
+/**
+ * Return a new copy of `buf`.
+ *
+ * If `buf` is `nil` or allocation fails, an error is yeeted.
+ *
+ * @param buf: Buffer to create a copy of
+ * @param err: Error pointer
+ * @returns A copy of `buf`, unless an error occurred
+ */
+nbuf_t *nbuf_clone(const nbuf_t *buf, error *err);
+
+/**
+ * Get the byte at the specified index.
+ *
+ * If `buf` is `nil` or `index` is out of bounds, an error is yeeted.
+ *
+ * @param buf: `nbuf_t *` to get the byte from
+ * @param index: Byte index (counting from 0)
+ * @param err: Error pointer
+ * @returns The byte at position `index` (as a `u8`), unless an error occurred
+ */
+#define nbuf_byte(buf, index, err) ({					\
+	u8 __byte = 0;							\
+	if (nlen(buf) <= index) {					\
+		yeet(err, ERANGE, "Buffer index out of bounds");	\
+	} else {							\
+		neat(err);						\
+		__byte = buf->_data[index];				\
+	}								\
+	__byte;								\
+})
+
+#define nbuf_foreach(cursor, buf)			\
+	for (cursor = &buf->_data[0];			\
+	     cursor != &buf->_data[nlen(buf)];		\
+	     cursor++)
+
+/**
+ * Compare two buffers.
+ *
+ * If the first buffer is found to be greater than the second one, the return
+ * value is greater than 0.
+ * If the two buffers are equal, the return value is zero.
+ * If the first buffer is found to be less than the second one, the return
+ * value is less than 0.
+ *
+ * If `buf1` or `buf2` is `nil`, an error is yeeted.
+ *
+ * @param buf1: First buffer to compare
+ * @param buf2: Second buffer to compare
+ * @param err: Error pointer
+ * @returns The difference between the buffers, unless an error occurred
+ */
+int nbuf_cmp(const nbuf_t *buf1, const nbuf_t *buf2, error *err);
+
+#define nbuf_eq(buf1, buf2, err) ( (bool)(nbuf_cmp(buf1, buf2, err) == 0) )
+
+/*
+ * This file is part of libneo.
+ * Copyright (c) 2021 Fefie <owo@fef.moe>.
+ *
+ * libneo is non-violent software: you may only use, redistribute,
+ * and/or modify it under the terms of the CNPLv6+ as found in
+ * the LICENSE file in the source code root directory or at
+ * <https://git.pixie.town/thufie/CNPL>.
+ *
+ * libneo comes with ABSOLUTELY NO WARRANTY, to the extent
+ * permitted by applicable law.  See the CNPLv6+ for details.
+ */

include/neo/_stddef.h

@@ -25,6 +25,18 @@
 	__neo_local_n < 0 ? -__neo_local_n : __neo_local_n;			\
 })
 
+#define nmax(x1, x2) ({			\
+	typeof(x1) __x1 = (x1);		\
+	typeof(x2) __x2 = (x2);		\
+	__x1 > __x2 ? __x1 : __x2;	\
+})
+
+#define nmin(x1, x2) ({			\
+	typeof(x1) __x1 = (x1);		\
+	typeof(x2) __x2 = (x2);		\
+	__x1 < __x2 ? __x1 : x2;	\
+})
+
 /**
  * Quickly get the length (as in amount of items, not bytes) of any libneo data
  * structure that supports it.  This includes strings, buffers, lists, and more.

include/neo/_types.h

@@ -64,11 +64,15 @@ struct _neo_nref {
 typedef struct _neo_nref nref_t;
 #define NREF_FIELD nref_t __neo_nref
 
-struct _neo_nmut {
-	__neo_atomic_type _lock;
+struct _neo_nbuf {
+	NREF_FIELD;
+	NLEN_FIELD(_size);
+	u8 _data[0];
 };
-typedef struct _neo_nmut nmut_t;
-#define NLOCK_FIELD nmut_t __neo_nmut
+/**
+ * A statically sized, refcounted buffer.
+ */
+typedef struct _neo_nbuf nbuf_t;
 
 struct _neo_string {
 	/* The *amount of Unicode code points*, NOT amount of bytes */

src/CMakeLists.txt

@@ -27,6 +27,7 @@ target_sources(neo PRIVATE
     ./error.c
     ./list.c
     ./nalloc.c
+    ./nbuf.c
     ./nref.c
 )
 

src/nbuf.c

@@ -0,0 +1,108 @@
+/** See the end of this file for copyright and license terms. */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "neo/_error.h"
+#include "neo/_nalloc.h"
+#include "neo/_nref.h"
+#include "neo/_stddef.h"
+#include "neo/_types.h"
+
+static void nbuf_destroy(struct _neo_nbuf *buf)
+{
+	nfree(buf);
+}
+
+nbuf_t *nbuf_create(usize size, error *err)
+{
+	if (size == 0) {
+		yeet(err, ERANGE, "Cannot create zero-size buffer");
+		return nil;
+	}
+
+	/*
+	 * Just like with strings, we allocate 4 extra bytes.
+	 * The buffer functions depend on this behavior, don't change.
+	 */
+	struct _neo_nbuf *buf = nalloc(sizeof(*buf) + size + 4, err);
+	catch(err) {
+		return nil;
+	}
+
+	buf->_size = size;
+
+	for (unsigned int i = 0; i < 4; i++)
+		buf->_data[size + i] = 0;
+
+	nref_init(buf, nbuf_destroy);
+	neat(err);
+	return buf;
+}
+
+nbuf_t *nbuf_from(const void *data, usize len, error *err)
+{
+	if (data == nil) {
+		yeet(err, EFAULT, "Data is nil");
+		return nil;
+	}
+
+	struct _neo_nbuf *buf = nbuf_create(len, err);
+	catch(err) {
+		return nil;
+	}
+
+	memcpy(&buf->_data[0], data, len);
+	return buf;
+}
+
+nbuf_t *nbuf_clone(const nbuf_t *buf, error *err)
+{
+	if (buf == nil) {
+		yeet(err, EFAULT, "Source buffer is nil");
+		return nil;
+	}
+
+	return nbuf_from(&buf->_data[0], nlen(buf), err);
+}
+
+int nbuf_cmp(const nbuf_t *buf1, const nbuf_t *buf2, error *err)
+{
+	if (buf1 == nil) {
+		yeet(err, EFAULT, "First buffer is nil");
+		if (buf2 == nil)
+			return 0;
+		else
+			return -1;
+	}
+	if (buf2 == nil) {
+		yeet(err, EFAULT, "Second buffer is nil");
+		return 1;
+	}
+
+	neat(err);
+
+	if (buf1 == buf2)
+		return 0;
+
+	/*
+	 * Extra byte because the two buffers might be of different size
+	 * (one of the reasons nbuf_create() allocates 4 bytes more than needed)
+	 */
+	usize maxbytes = nmin(nlen(buf1), nlen(buf2)) + 1;
+	return memcmp(&buf1->_data[0], &buf2->_data[0], maxbytes);
+}
+
+/*
+ * This file is part of libneo.
+ * Copyright (c) 2021 Fefie <owo@fef.moe>.
+ *
+ * libneo is non-violent software: you may only use, redistribute,
+ * and/or modify it under the terms of the CNPLv6+ as found in
+ * the LICENSE file in the source code root directory or at
+ * <https://git.pixie.town/thufie/CNPL>.
+ *
+ * libneo comes with ABSOLUTELY NO WARRANTY, to the extent
+ * permitted by applicable law.  See the CNPLv6+ for details.
+ */

test/CMakeLists.txt

@@ -20,6 +20,7 @@ include(string/string.cmake)
 
 target_sources(neo_test PRIVATE
     list.cpp
+    nbuf.cpp
     nref.cpp
 )
 

test/nbuf.cpp

@@ -0,0 +1,229 @@
+/** See the end of this file for copyright and license terms. */
+
+#include <catch2/catch.hpp>
+#include <errno.h>
+#include <string.h>
+
+#include <neo.h>
+
+TEST_CASE( "nbuf_create: Create regular buffer", "[src/nbuf.c]" )
+{
+	error err;
+	nbuf_t *buf = nbuf_create(32, &err);
+
+	REQUIRE( buf != nil );
+	REQUIRE( nlen(buf) == 32 );
+	REQUIRE( errnum(&err) == 0 );
+}
+
+TEST_CASE( "nbuf_create: Error if size is 0", "[src/nbuf.c]" )
+{
+	error err;
+	nbuf_t *buf = nbuf_create(0, &err);
+	string *expected_msg = nstr("Cannot create zero-size buffer", nil);
+
+	REQUIRE( buf == nil );
+	REQUIRE( errnum(&err) == ERANGE );
+	REQUIRE( nstreq(errmsg(&err), expected_msg, nil) );
+	errput(&err);
+	nput(expected_msg);
+}
+
+TEST_CASE( "nbuf_from: Copy data", "[src/nbuf.c]" )
+{
+	error err;
+	const char *data = "i'm gay,,,";
+	usize size = strlen(data);
+	nbuf_t *buf = nbuf_from(data, size, &err);
+
+	REQUIRE( buf != nil );
+	REQUIRE( nlen(buf) == size );
+	REQUIRE( errnum(&err) == 0 );
+	REQUIRE( memcmp(data, &buf->_data[0], size) == 0 );
+
+	nput(buf);
+}
+
+TEST_CASE( "nbuf_from: Error if data is nil", "[src/nbuf.c]" )
+{
+	error err;
+	nbuf_t *buf = nbuf_from(nil, 1, &err);
+
+	string *expected_msg = nstr("Data is nil", nil);
+
+	REQUIRE( buf == nil );
+	REQUIRE( errnum(&err) == EFAULT );
+	REQUIRE( nstreq(expected_msg, errmsg(&err), nil) );
+
+	errput(&err);
+	nput(expected_msg);
+}
+
+TEST_CASE( "nbuf_from: Error if size is 0", "[src/nbuf.c]" )
+{
+	error err;
+	const char *data = "i'm gay,,,";
+	nbuf_t *buf = nbuf_from(data, 0, &err);
+
+	string *expected_msg = nstr("Cannot create zero-size buffer", nil);
+
+	REQUIRE( buf == nil );
+	REQUIRE( errnum(&err) == ERANGE );
+	REQUIRE( nstreq(expected_msg, errmsg(&err), nil) );
+
+	errput(&err);
+	nput(expected_msg);
+}
+
+TEST_CASE( "nbuf_clone: Copy data", "[src/nbuf.c]" )
+{
+	error err;
+	const char *data = "i'm gay,,,";
+	usize size = strlen(data);
+
+	nbuf_t *original = nbuf_from(data, size, nil);
+	nbuf_t *clone = nbuf_clone(original, &err);
+
+	REQUIRE( clone != nil );
+	REQUIRE( nlen(clone) == nlen(original) );
+	REQUIRE( errnum(&err) == 0 );
+	REQUIRE( memcmp(data, &clone->_data[0], size) == 0 );
+
+	nput(original);
+	nput(clone);
+}
+
+TEST_CASE( "nbuf_clone: Error if original buffer is nil", "[src/nbuf.c]" )
+{
+	error err;
+	nbuf_t *buf = nbuf_clone(nil, &err);
+
+	string *expected_msg = nstr("Source buffer is nil", nil);
+
+	REQUIRE( buf == nil );
+	REQUIRE( errnum(&err) == EFAULT );
+	REQUIRE( nstreq(expected_msg, errmsg(&err), nil) );
+
+	errput(&err);
+	nput(expected_msg);
+}
+
+TEST_CASE( "nbuf_cmp: Return 0 if buffers are equal", "[src/nbuf.c]" )
+{
+	error err;
+	const char *data = "aaaaa";
+	usize size = strlen(data);
+
+	nbuf_t *original = nbuf_from(data, size, nil);
+	nbuf_t *clone = nbuf_clone(original, nil);
+
+	int diff = nbuf_cmp(original, clone, &err);
+
+	REQUIRE( diff == 0 );
+	REQUIRE( errnum(&err) == 0 );
+
+	nput(original);
+	nput(clone);
+}
+
+TEST_CASE( "nbuf_cmp: Return positive if buffer 1 > buffer 2", "[src/nbuf.c]" )
+{
+	error err;
+	const char *data = "aaaaa";
+	usize size = strlen(data);
+
+	nbuf_t *buf1 = nbuf_from(data, size, nil);
+	nbuf_t *buf2 = nbuf_from(data, size - 1, nil);
+
+	int diff = nbuf_cmp(buf1, buf2, &err);
+
+	REQUIRE( diff > 0 );
+	REQUIRE( errnum(&err) == 0 );
+
+	nput(buf1);
+	nput(buf2);
+}
+
+TEST_CASE( "nbuf_cmp: Return negative if buffer 1 < buffer 2", "[src/nbuf.c]" )
+{
+	error err;
+	const char *data = "aaaaa";
+	usize size = strlen(data);
+
+	nbuf_t *buf1 = nbuf_from(data, size - 1, nil);
+	nbuf_t *buf2 = nbuf_from(data, size, nil);
+
+	int diff = nbuf_cmp(buf1, buf2, &err);
+
+	REQUIRE( diff < 0 );
+	REQUIRE( errnum(&err) == 0 );
+
+	nput(buf1);
+	nput(buf2);
+}
+
+TEST_CASE( "nbuf_cmp: Error if first buffer is nil", "[src/nbuf.c]" )
+{
+	error err;
+	const char *data = "aaaaa";
+	usize size = strlen(data);
+
+	nbuf_t *buf2 = nbuf_from(data, size, nil);
+	int diff = nbuf_cmp(nil, buf2, &err);
+
+	string *expected_msg = nstr("First buffer is nil", nil);
+
+	REQUIRE( diff < 0 );
+	REQUIRE( errnum(&err) == EFAULT );
+	REQUIRE( nstreq(expected_msg, errmsg(&err), nil) );
+
+	errput(&err);
+	nput(buf2);
+}
+
+TEST_CASE( "nbuf_cmp: Error if second buffer is nil", "[src/nbuf.c]" )
+{
+	error err;
+	const char *data = "aaaaa";
+	usize size = strlen(data);
+
+	nbuf_t *buf1 = nbuf_from(data, size, nil);
+	int diff = nbuf_cmp(buf1, nil, &err);
+
+	string *expected_msg = nstr("Second buffer is nil", nil);
+
+	REQUIRE( diff > 0 );
+	REQUIRE( errnum(&err) == EFAULT );
+	REQUIRE( nstreq(expected_msg, errmsg(&err), nil) );
+
+	errput(&err);
+	nput(buf1);
+}
+
+TEST_CASE( "nbuf_cmp: Error if both buffers are nil", "[src/nbuf.c]" )
+{
+	error err;
+
+	int diff = nbuf_cmp(nil, nil, &err);
+
+	string *expected_msg = nstr("First buffer is nil", nil);
+
+	REQUIRE( diff == 0 );
+	REQUIRE( errnum(&err) == EFAULT );
+	REQUIRE( nstreq(expected_msg, errmsg(&err), nil) );
+
+	errput(&err);
+}
+
+/*
+ * This file is part of libneo.
+ * Copyright (c) 2021 Fefie <owo@fef.moe>.
+ *
+ * libneo is non-violent software: you may only use, redistribute,
+ * and/or modify it under the terms of the CNPLv6+ as found in
+ * the LICENSE file in the source code root directory or at
+ * <https://git.pixie.town/thufie/CNPL>.
+ *
+ * libneo comes with ABSOLUTELY NO WARRANTY, to the extent
+ * permitted by applicable law.  See the CNPLv6+ for details.
+ */