From: Nathan Wagner <nw@hydaspes.if.org>
Date: Tue, 26 Feb 2019 05:51:17 +0000 (+0000)
Subject: add buffer lib files
X-Git-Tag: v0.7.0~13
X-Git-Url: https://pd.if.org/git/?p=zpackage;a=commitdiff_plain;h=290e4a5a70804333d0d0060035292ebe1cc758cd

add buffer lib files
---

diff --git a/lib/buffer.c b/lib/buffer.c
new file mode 100644
index 0000000..adf7ab8
--- /dev/null
+++ b/lib/buffer.c
@@ -0,0 +1,277 @@
+#define _POSIX_C_SOURCE 200809L
+
+#include <string.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "buffer.h"
+
+void zpm_buffer_init(struct zpm_buffer *buffer) {
+	buffer->buffer = 0;
+	buffer->len = 0;
+	buffer->size = 0;
+	buffer->error = 0;
+}
+
+void zpm_buffer_compact(struct zpm_buffer *b) {
+	void *new;
+
+	if (b->error || b->size == b->len) {
+		return;
+	}
+
+	errno = 0;
+	new = realloc(b->buffer, b->len);
+
+	if (new == NULL) {
+		b->error = errno;
+		return;
+	}
+
+	b->buffer = new;
+	return;
+}
+
+/* makes sure there's at least need bytes free */
+void zpm_buffer_expand(struct zpm_buffer *buf, size_t need) {
+	size_t want;
+
+	if (buf->error) {
+		return;
+	}
+
+	want = buf->len + need;
+
+	if (want <= buf->size) {
+		return;
+	}
+
+	errno = 0;
+	char *new = realloc(buf->buffer, want);
+	if (new) {
+		buf->buffer = new;
+		buf->size = want;
+		memset(buf->buffer + buf->len, 0, buf->size - buf->len);
+	} else {
+		buf->error = errno;
+	}
+}
+
+void zpm_buffer_free(struct zpm_buffer *buffer) {
+	/* TODO only zero out memory if it's "secure" buffer */
+	if (buffer->buffer && buffer->len) {
+		memset(buffer->buffer, 0, buffer->len);
+	}
+	free(buffer->buffer);
+	zpm_buffer_init(buffer);
+}
+
+void zpm_buffer_set(struct zpm_buffer *buffer, int ch) {
+	/* TODO only zero out memory if it's "secure" buffer */
+	if (buffer->buffer && buffer->size) {
+		memset(buffer->buffer, ch, buffer->size);
+	}
+}
+
+void zpm_buffer_appendvf(struct zpm_buffer *buf, const char *fmt, va_list ap) {
+	int len;
+	va_list ar;
+
+	va_copy(ar, ap);
+	len = vsnprintf(0, 0, fmt, ar);
+	va_end(ar);
+
+	zpm_buffer_expand(buf, len+1);
+	vsprintf(buf->buffer + buf->len, fmt, ap);
+}
+
+void zpm_buffer_appendf(struct zpm_buffer *buf, const char *fmt, ...) {
+	va_list ap;
+	int len;
+
+	va_start(ap, fmt);
+	len = vsnprintf(0, 0, fmt, ap);
+	va_end(ap);
+	zpm_buffer_expand(buf, len+1);
+	va_start(ap, fmt);
+	vsprintf(buf->buffer + buf->len, fmt, ap);
+	va_end(ap);
+}
+
+void zpm_buffer_append(struct zpm_buffer *buffer, const unsigned char *bytes, size_t n) {
+	zpm_buffer_expand(buffer, n);
+
+	if (buffer->error || !bytes) {
+		return;
+	}
+
+	memcpy(buffer->buffer + buffer->len, bytes, n);
+	buffer->len += n;
+}
+
+void zpm_buffer_append_str(struct zpm_buffer *buf, const char *s) {
+	zpm_buffer_append(buf, (const unsigned char *)s, strlen(s));
+}
+
+void zpm_buffer_append16(struct zpm_buffer *buffer, uint16_t n) {
+	zpm_buffer_expand(buffer, 2);
+
+	if (buffer->error) {
+		return;
+	}
+
+	buffer->buffer[buffer->len++] = (n >> 8) & 0xff;
+	buffer->buffer[buffer->len++] = n & 0xff;
+}
+
+void zpm_buffer_append24(struct zpm_buffer *buffer, uint32_t n) {
+	zpm_buffer_expand(buffer, 3);
+
+	if (buffer->error) {
+		return;
+	}
+
+	buffer->buffer[buffer->len++] = (n >> 16) & 0xff;
+	buffer->buffer[buffer->len++] = (n >> 8) & 0xff;
+	buffer->buffer[buffer->len++] = n & 0xff;
+}
+
+void zpm_buffer_append_byte(struct zpm_buffer *buffer, uint8_t n) {
+	zpm_buffer_expand(buffer, 1);
+
+	if (buffer->error) {
+		return;
+	}
+
+	buffer->buffer[buffer->len++] = n & 0xff;
+}
+
+void zpm_buffer_write16(struct zpm_buffer *buffer, uint16_t n, size_t at) {
+	if (at+2 > buffer->size) {
+		zpm_buffer_expand(buffer, at+2 - buffer->size);
+	}
+
+	if (buffer->error) {
+		return;
+	}
+
+	buffer->buffer[at] = (n >> 8) & 0xff;
+	buffer->buffer[at+1] = n & 0xff;
+
+	if (at+2 > buffer->len) {
+		buffer->len = at + 2;
+	}
+}
+
+uint16_t zpm_buffer_read16(struct zpm_buffer *buffer, size_t at) {
+	uint16_t res = 0;
+
+	if (buffer->error || at+2 < buffer->len) {
+		return 0;
+	}
+
+	res = (buffer->buffer[at] << 8) + buffer->buffer[at+1];
+	return res;
+}
+
+uint64_t zpm_buffer_readbe(struct zpm_buffer *buffer, int bytes, size_t at) {
+	uint16_t res = 0;
+	int i;
+
+	if (buffer->error || at+bytes < buffer->len) {
+		return 0;
+	}
+
+	for (i=0; i<bytes; i++) {
+		res <<= 8;
+		res += buffer->buffer[at+i];
+	}
+
+	return res;
+}
+
+void zpm_buffer_writebe(struct zpm_buffer *buffer, int bytes, size_t at, uint64_t val) {
+	int i;
+	if (at+bytes > buffer->size) {
+		zpm_buffer_expand(buffer, at+bytes - buffer->size);
+	}
+
+	if (buffer->error) {
+		return;
+	}
+
+	for (i=bytes-1; i>=0; i--) {
+		buffer->buffer[at+i] = val & 0xff;
+		val >>= 8;
+	}
+
+	return;
+}
+
+void zpm_buffer_shift(struct zpm_buffer *buffer, size_t n) {
+	if (buffer->error) {
+		return;
+	}
+
+	if (buffer->len < n) {
+		n = buffer->len;
+	}
+
+	if (n) {
+		memmove(buffer->buffer, buffer->buffer + n, buffer->len - n);
+		memset(buffer->buffer + buffer->len - n, 0, n);
+#if 0
+		fprintf(stderr, "memmove(%p, %p, %zu)\n", buffer->buffer,
+				buffer->buffer+n, buffer->len - n);
+		fprintf(stderr, "memset(%p, %d, %zu)\n", buffer->buffer+n,
+				0, n);
+#endif
+
+		buffer->len -= n;
+	}
+}
+
+/* make room at the beginning */
+void zpm_buffer_unshift(struct zpm_buffer *buffer, size_t n) {
+	zpm_buffer_expand(buffer, n);
+
+	if (buffer->error) {
+		return;
+	}
+
+	memmove(buffer->buffer + n, buffer->buffer, n);
+	memset(buffer->buffer, 0, n);
+}
+
+#if 0
+uint32_t zpm_buffer_next3(struct zpm_buffer_reader *rb) {
+	uint32_t r;
+
+	r = zpm_buffer_readbe(rb, 3, rb->cursor);
+	rb->cursor += 3;
+	return r;
+}
+
+uint16_t zpm_buffer_next2(struct zpm_buffer_reader *rb) {
+	uint16_t r;
+
+	r = zpm_buffer_readbe(rb, 2, rb->cursor);
+	rb->cursor += 2;
+	return r;
+}
+
+uint8_t zpm_buffer_next(struct zpm_buffer_reader *rb) {
+	uint16_t r;
+
+	r = zpm_buffer_readbe(rb, 2, rb->cursor);
+	rb->cursor += 2;
+
+}
+
+void zpm_buffer_nextn(struct zpm_buffer_reader *rb, unsigned char *b, size_t n) {
+	zpm_buffer_read(rb, b, n, rb->cursor);
+	rb->cursor += n;
+}
+#endif
diff --git a/lib/buffer.h b/lib/buffer.h
new file mode 100644
index 0000000..7a849d8
--- /dev/null
+++ b/lib/buffer.h
@@ -0,0 +1,53 @@
+#ifndef ZPM_BUFFER_H_
+#define ZPM_BUFFER_H_ 1
+
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+
+/* flags:
+ * 0x1 secure: zero memory when used
+ * 0x2 fixed: buffer doesn't belong to you, and size says how big it is
+ * 0x4 
+ */
+struct zpm_buffer {
+	char *buffer;
+	size_t len;
+	size_t size;
+	int32_t error;
+	uint32_t flags;
+};
+
+struct zpm_buffer_reader {
+	struct zpm_buffer b;
+	size_t cursor;
+};
+
+uint32_t zpm_buffer_next3(struct zpm_buffer_reader *rb);
+uint16_t zpm_buffer_next2(struct zpm_buffer_reader *rb);
+uint8_t zpm_buffer_next(struct zpm_buffer_reader *rb);
+void zpm_buffer_nextn(struct zpm_buffer_reader *rb, unsigned char *b, size_t n);
+
+void zpm_buffer_init(struct zpm_buffer *b); 
+
+/* makes sure there's at least need bytes free */
+void zpm_buffer_expand(struct zpm_buffer *b, size_t need);
+void zpm_buffer_free(struct zpm_buffer *b);
+void zpm_buffer_set(struct zpm_buffer *buffer, int ch);
+void zpm_buffer_compact(struct zpm_buffer *b);
+void zpm_buffer_append(struct zpm_buffer *b, const unsigned char *bytes, size_t n);
+void zpm_buffer_appendf(struct zpm_buffer *b, const char *fmt, ...);
+void zpm_buffer_appendvf(struct zpm_buffer *b, const char *fmt, va_list ap);
+void zpm_buffer_append_str(struct zpm_buffer *b, const char *s);
+void zpm_buffer_append16(struct zpm_buffer *b, uint16_t n);
+void zpm_buffer_append24(struct zpm_buffer *b, uint32_t n);
+void zpm_buffer_append_byte(struct zpm_buffer *b, uint8_t n);
+void zpm_buffer_shift(struct zpm_buffer *b, size_t n);
+void zpm_buffer_write16(struct zpm_buffer *b, uint16_t n, size_t at);
+void zpm_buffer_writebe(struct zpm_buffer *b, int bytes, size_t at, uint64_t val);
+uint64_t zpm_buffer_readbe(struct zpm_buffer *b, int bytes, size_t at);
+
+/* make room at the beginning */
+void zpm_buffer_unshift(struct zpm_buffer *b, size_t n);
+
+#endif