fx: implement byte-oriented memory stream class

2026-07-05 15:59:41 +01:00
parent 50706084eb
commit dbd2135998
2 changed files with 320 additions and 0 deletions
@@ -0,0 +1,283 @@
+#include <fx/bytestream.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define DEFAULT_CAPACITY 128
+
+/*** PRIVATE DATA *************************************************************/
+
+struct fx_bytestream_p {
+	unsigned char *s_buf;
+	size_t s_ptr;
+	size_t s_len;
+	size_t s_max;
+	unsigned char s_alloc;
+};
+
+/*** PRIVATE FUNCTIONS ********************************************************/
+
+static enum fx_status __gets(
+	struct fx_bytestream_p *s,
+	unsigned char *buf,
+	size_t len,
+	size_t *nr_read)
+{
+	size_t available = s->s_len - s->s_ptr;
+	size_t to_copy = len;
+
+	if (available < to_copy) {
+		to_copy = available;
+	}
+
+	memcpy(buf, s->s_buf + s->s_ptr, to_copy);
+
+	s->s_ptr += to_copy;
+
+	if (s->s_ptr == s->s_len) {
+		s->s_ptr = s->s_len = 0;
+	}
+
+	if (nr_read) {
+		*nr_read = to_copy;
+	}
+
+	return FX_SUCCESS;
+}
+
+static enum fx_status __puts(
+	struct fx_bytestream_p *s,
+	const unsigned char *buf,
+	size_t len,
+	size_t *nr_written)
+{
+	size_t available = s->s_max - s->s_len;
+	size_t to_copy = len;
+
+	if (to_copy > available && s->s_alloc == 1) {
+		unsigned char *new_buf
+			= realloc(s->s_buf, s->s_len + to_copy + 1);
+		if (!new_buf) {
+			return FX_ERR_NO_MEMORY;
+		}
+
+		s->s_buf = new_buf;
+		s->s_max = s->s_len + to_copy;
+		available = s->s_max - s->s_len;
+	}
+
+	if (available < to_copy) {
+		to_copy = available;
+	}
+
+	memcpy(s->s_buf + s->s_len, buf, to_copy);
+	s->s_buf[s->s_len + to_copy] = 0;
+
+	/* increment the length by the full byte length, even if only a
+	 * portion was copied */
+	s->s_len += len;
+
+	if (nr_written) {
+		*nr_written = to_copy;
+	}
+
+	return FX_SUCCESS;
+}
+
+static enum fx_status bytestream_reset(struct fx_bytestream_p *s)
+{
+	s->s_len = 0;
+
+	if (s->s_buf) {
+		*s->s_buf = 0;
+	}
+
+	return FX_SUCCESS;
+}
+
+static size_t bytestream_get_length(const struct fx_bytestream_p *strv)
+{
+	return strv->s_len;
+}
+
+static const unsigned char *bytestream_get_ptr(const struct fx_bytestream_p *s)
+{
+	return s->s_buf;
+}
+
+static unsigned char *bytestream_steal(struct fx_bytestream_p *s)
+{
+	unsigned char *out = s->s_buf;
+
+	memset(s, 0x0, sizeof *s);
+
+	s->s_alloc = 1;
+
+	return out;
+}
+
+/*** PUBLIC FUNCTIONS *********************************************************/
+
+fx_bytestream *fx_bytestream_create_view(unsigned char *buf, size_t max)
+{
+	fx_bytestream *s = fx_object_create(FX_TYPE_BYTESTREAM);
+	if (!s) {
+		return NULL;
+	}
+
+	fx_stream_cfg *cfg = fx_object_get_protected(s, FX_TYPE_STREAM);
+	struct fx_bytestream_p *p
+		= fx_object_get_private(s, FX_TYPE_BYTESTREAM);
+
+	cfg->s_mode = FX_STREAM_READ | FX_STREAM_WRITE | FX_STREAM_BINARY
+	            | Z__FX_STREAM_STATIC;
+
+	p->s_buf = buf;
+	p->s_max = max;
+	p->s_len = max;
+	p->s_alloc = 0;
+
+	return s;
+}
+
+fx_bytestream *fx_bytestream_create_readonly_view(
+	const unsigned char *buf,
+	size_t max)
+{
+	fx_bytestream *s = fx_object_create(FX_TYPE_BYTESTREAM);
+	if (!s) {
+		return NULL;
+	}
+
+	fx_stream_cfg *cfg = fx_object_get_protected(s, FX_TYPE_STREAM);
+	struct fx_bytestream_p *p
+		= fx_object_get_private(s, FX_TYPE_BYTESTREAM);
+
+	cfg->s_mode = FX_STREAM_READ | FX_STREAM_BINARY | Z__FX_STREAM_STATIC;
+
+	p->s_buf = (unsigned char *)buf;
+	p->s_max = max;
+	p->s_len = max;
+	p->s_alloc = 0;
+
+	return s;
+}
+
+fx_bytestream *fx_bytestream_create(void)
+{
+	fx_bytestream *s = fx_object_create(FX_TYPE_BYTESTREAM);
+	if (!s) {
+		return NULL;
+	}
+
+	fx_stream_cfg *cfg = fx_object_get_protected(s, FX_TYPE_STREAM);
+	struct fx_bytestream_p *p
+		= fx_object_get_private(s, FX_TYPE_BYTESTREAM);
+
+	cfg->s_mode = FX_STREAM_READ | FX_STREAM_WRITE | FX_STREAM_BINARY
+	            | Z__FX_STREAM_STATIC;
+
+	p->s_buf = malloc(DEFAULT_CAPACITY + 1);
+	if (!p->s_buf) {
+		fx_bytestream_unref(s);
+		return NULL;
+	}
+
+	memset(p->s_buf, 0x0, DEFAULT_CAPACITY + 1);
+	p->s_max = DEFAULT_CAPACITY;
+	p->s_len = 0;
+	p->s_alloc = 1;
+
+	return s;
+}
+
+size_t fx_bytestream_get_length(const fx_bytestream *strv)
+{
+	FX_CLASS_DISPATCH_STATIC_0(
+		FX_TYPE_BYTESTREAM,
+		bytestream_get_length,
+		strv);
+}
+
+enum fx_status fx_bytestream_reset(fx_bytestream *strv)
+{
+	FX_CLASS_DISPATCH_STATIC_0(FX_TYPE_BYTESTREAM, bytestream_reset, strv);
+}
+
+const unsigned char *fx_bytestream_get_ptr(const fx_bytestream *s)
+{
+	FX_CLASS_DISPATCH_STATIC_0(FX_TYPE_BYTESTREAM, bytestream_get_ptr, s);
+}
+
+unsigned char *fx_bytestream_steal(fx_bytestream *s)
+{
+	FX_CLASS_DISPATCH_STATIC_0(FX_TYPE_BYTESTREAM, bytestream_steal, s);
+}
+
+/*** VIRTUAL FUNCTIONS ********************************************************/
+
+static void bytestream_init(fx_object *obj, void *priv)
+{
+	struct fx_bytestream_p *stream = priv;
+}
+
+static void bytestream_fini(fx_object *obj, void *priv)
+{
+	struct fx_bytestream_p *stream = priv;
+
+	if (stream->s_alloc && stream->s_buf) {
+		free(stream->s_buf);
+	}
+}
+
+static enum fx_status stream_read(
+	fx_stream *stream,
+	void *buf,
+	size_t count,
+	size_t *nr_read)
+{
+	struct fx_bytestream_p *s
+		= fx_object_get_private(stream, FX_TYPE_BYTESTREAM);
+
+	enum fx_status status = __gets(s, buf, count, nr_read);
+
+	return status;
+}
+
+static enum fx_status stream_write(
+	fx_stream *stream,
+	const void *buf,
+	size_t count,
+	size_t *nr_written)
+{
+	struct fx_bytestream_p *s
+		= fx_object_get_private(stream, FX_TYPE_BYTESTREAM);
+
+	enum fx_status status
+		= __puts(s, (const unsigned char *)buf, count, nr_written);
+
+	return status;
+}
+
+/*** CLASS DEFINITION *********************************************************/
+
+FX_TYPE_CLASS_BEGIN(fx_bytestream)
+	FX_TYPE_VTABLE_INTERFACE_BEGIN(fx_stream, FX_TYPE_STREAM)
+		FX_INTERFACE_ENTRY(s_close) = NULL;
+		FX_INTERFACE_ENTRY(s_seek) = NULL;
+		FX_INTERFACE_ENTRY(s_tell) = NULL;
+		FX_INTERFACE_ENTRY(s_getc) = NULL;
+		FX_INTERFACE_ENTRY(s_read) = stream_read;
+		FX_INTERFACE_ENTRY(s_write) = stream_write;
+		FX_INTERFACE_ENTRY(s_reserve) = NULL;
+	FX_TYPE_VTABLE_INTERFACE_END(fx_stream, FX_TYPE_STREAM)
+FX_TYPE_CLASS_END(fx_bytestream)
+
+FX_TYPE_DEFINITION_BEGIN(fx_bytestream)
+	FX_TYPE_ID(0xdcb7fb3a, 0xc476, 0x4c0b, 0xad5a, 0x039d1190a5b7);
+	FX_TYPE_EXTENDS(FX_TYPE_STREAM);
+	FX_TYPE_CLASS(fx_bytestream_class);
+	FX_TYPE_INSTANCE_PRIVATE(struct fx_bytestream_p);
+	FX_TYPE_INSTANCE_INIT(bytestream_init);
+	FX_TYPE_INSTANCE_FINI(bytestream_fini);
+FX_TYPE_DEFINITION_END(fx_bytestream)
@@ -0,0 +1,37 @@
+#ifndef FX_CORE_BYTESTREAM_H_
+#define FX_CORE_BYTESTREAM_H_
+
+#include <fx/macros.h>
+#include <fx/misc.h>
+#include <fx/status.h>
+#include <fx/stream.h>
+#include <stddef.h>
+
+FX_DECLS_BEGIN;
+
+#define FX_TYPE_BYTESTREAM (fx_bytestream_get_type())
+
+FX_DECLARE_TYPE(fx_bytestream);
+
+FX_TYPE_CLASS_DECLARATION_BEGIN(fx_bytestream)
+FX_TYPE_CLASS_DECLARATION_END(fx_bytestream)
+
+FX_API fx_type_id fx_bytestream_get_type(void);
+
+FX_API fx_bytestream *fx_bytestream_create(void);
+FX_API fx_bytestream *fx_bytestream_create_view(unsigned char *buf, size_t max);
+FX_API fx_bytestream *fx_bytestream_create_readonly_view(
+	const unsigned char *buf,
+	size_t max);
+
+FX_API fx_status fx_bytestream_reset(fx_bytestream *strv);
+
+FX_API const unsigned char *fx_bytestream_get_ptr(const fx_bytestream *strv);
+FX_API unsigned char *fx_bytestream_steal(fx_bytestream *strv);
+
+FX_API size_t fx_bytestream_get_length(const fx_bytestream *strv);
+FX_API size_t fx_bytestream_get_available(const fx_bytestream *strv);
+
+FX_DECLS_END;
+
+#endif