s3-lib: add cbuf, a talloced character buffer

Signed-off-by: Michael Adam <obnox@samba.org>

2 files changed, 522 insertions, 0 deletions

diff --git a/source3/lib/cbuf.c b/source3/lib/cbuf.c
new file mode 100644
index 0000000000..85d1c14d45
--- /dev/null
+++ b/source3/lib/cbuf.c
@@ -0,0 +1,287 @@
+/*
+ * Samba Unix/Linux SMB client library
+ *
+ * Copyright (C) Gregor Beck 2010
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @file   cbuf.c
+ * @author Gregor Beck <gb@sernet.de>
+ * @date   Aug 2010
+ *
+ * @brief  A talloced character buffer.
+ *
+ */
+
+
+#include <assert.h>
+#include "includes.h"
+#include "cbuf.h"
+
+
+struct cbuf {
+	char*  buf;
+	size_t pos;
+	size_t size;
+};
+
+
+cbuf* cbuf_clear(cbuf* b)
+{
+	cbuf_setpos(b, 0);
+	return b;
+}
+
+cbuf* cbuf_new(const void* ctx)
+{
+	cbuf* s = talloc(ctx, cbuf);
+	if (s == NULL)
+		return NULL;
+	s->size = 32;
+	s->buf  = talloc_size(s, s->size);
+	if (s->size && (s->buf == NULL)) {
+		talloc_free(s);
+		return NULL;
+	}
+	return cbuf_clear(s);
+}
+
+cbuf* cbuf_copy(const cbuf* b)
+{
+	cbuf* s = talloc(talloc_parent(b), cbuf);
+	if (s == NULL) {
+		return NULL;
+	}
+
+	s->buf = talloc_memdup(s, b->buf, b->size); /* only up to pos? */
+
+	/* XXX shallow did not work, because realloc */
+	/* fails with multiple references */
+	/* s->buf = talloc_reference(s, b->buf); */
+
+	if (s->buf == NULL) {
+		cbuf_delete(s);
+		return NULL;
+	}
+	s->size = b->size;
+	s->pos  = b->pos;
+	return s;
+}
+
+void cbuf_delete(cbuf* b)
+{
+	talloc_free(b);
+}
+
+#define SWAP(A,B,T) do {			\
+		T tmp = A; A = B; B = tmp;	\
+	} while(0)
+
+
+void cbuf_swap(cbuf* b1, cbuf* b2)
+{
+	if (b1 == b2) {
+		return;
+	}
+	talloc_reparent(b1, b2, b1->buf);
+	talloc_reparent(b2, b1, b2->buf);
+	SWAP(b1->buf,  b2->buf, char*);
+	SWAP(b1->pos,  b2->pos, size_t);
+	SWAP(b1->size, b2->size, size_t);
+}
+
+
+
+cbuf* cbuf_takeover(cbuf* b1, cbuf* b2)
+{
+	talloc_reparent(b2, b1, b2->buf);
+	b1->buf = b2->buf;
+	b1->pos = b2->pos;
+	b1->size = b2->size;
+	cbuf_delete(b2);
+	return b1;
+}
+
+cbuf* cbuf_swapptr(cbuf* b, char** ptr, size_t len)
+{
+	SWAP(b->buf, *ptr, char*);
+	talloc_steal(b, b->buf);
+	b->size = talloc_get_size(b->buf);
+	b->pos  = (len == -1) ? strlen(b->buf) : len;
+
+	assert(b->pos <= b->size);
+	return b;
+}
+
+cbuf* cbuf_resize(cbuf* b, size_t size)
+{
+	char* save_buf = b->buf;
+	b->buf = talloc_realloc(b, b->buf, char, size);
+	if (b->buf == NULL) {
+		talloc_free(save_buf);
+		b->size = 0;
+	} else {
+		b->size = size;
+	}
+	b->pos  = MIN(b->pos, b->size);
+	return b->buf ? b : NULL;
+}
+
+char* cbuf_reserve(cbuf* b, size_t len)
+{
+	if(b->size < b->pos + len)
+		cbuf_resize(b, MAX(2*b->size, b->pos + len));
+	return b->buf ? b->buf + b->pos : NULL;
+}
+
+int cbuf_puts(cbuf* b, const char* str, size_t len)
+{
+	char* dst;
+
+	if (b == NULL)
+		return 0;
+
+	if (len == -1) {
+		len=strlen(str);
+	}
+
+	dst = cbuf_reserve(b, len+1);
+	if (dst == NULL)
+		return -1;
+
+	memcpy(dst, str, len);
+	dst[len] = '\0'; /* just to ease debugging */
+
+	b->pos += len;
+	assert(b->pos < b->size);
+
+	return len;
+}
+
+int cbuf_putc(cbuf* b, char c) {
+	char* dst;
+
+	if (b == NULL)
+		return 0;
+
+	dst = cbuf_reserve(b, 2);
+	if (dst == NULL) {
+		return -1;
+	}
+
+	dst[0] = c;
+	dst[1] = '\0'; /* just to ease debugging */
+
+	b->pos++;
+	assert(b->pos < b->size);
+
+	return 1;
+}
+
+int cbuf_putdw(cbuf* b, uint32_t u) {
+	char* dst;
+	static const size_t LEN = sizeof(uint32_t);
+
+	if (b == NULL)
+		return 0;
+
+	dst = cbuf_reserve(b, LEN);
+	if (dst == NULL) {
+		return -1;
+	}
+
+	SIVAL(dst, 0, u);
+
+	b->pos += LEN;
+	assert(b->pos <= b->size); /* no NULL termination*/
+
+	return LEN;
+}
+
+size_t cbuf_getpos(const cbuf* b) {
+	assert(b->pos <= b->size);
+	return b->pos;
+}
+
+void cbuf_setpos(cbuf* b, size_t pos) {
+	assert(pos <= b->size);
+	b->pos = pos;
+	if (pos < b->size)
+		b->buf[pos] = '\0'; /* just to ease debugging */
+}
+
+char* cbuf_gets(cbuf* b, size_t idx) {
+	assert(idx <= b->pos);
+
+	if (cbuf_reserve(b, 1) == NULL)
+		return NULL;
+
+	b->buf[b->pos] = '\0';
+	return b->buf + idx;
+}
+
+int cbuf_printf(cbuf* b, const char* fmt, ...)
+{
+	va_list args, args2;
+	int len;
+	char* dst = b->buf + b->pos;
+	const int avail = b->size - b->pos;
+	assert(avail >= 0);
+
+	va_start(args, fmt);
+	va_copy(args2, args);
+
+	len = vsnprintf(dst, avail, fmt, args);
+
+	if (len >= avail) {
+		dst = cbuf_reserve(b, len+1);
+		len = (dst != NULL) ? vsnprintf(dst, len+1, fmt, args2) : -1;
+	}
+
+	if (len > 0) {
+		b->pos += len;
+	}
+
+	va_end(args);
+	va_end(args2);
+	assert(b->pos <= b->size);
+
+	return len;
+}
+
+int cbuf_print_quoted_string(cbuf* ost, const char* s)
+{
+	int n = 1;
+	cbuf_putc(ost,'"');
+
+	while(true) {
+		switch (*s) {
+		case '\0':
+			cbuf_putc(ost, '"');
+			return n+1;
+
+		case '"':
+		case '\\':
+			cbuf_putc(ost, '\\');
+		        n++;
+			/* no break */
+		default:
+			cbuf_putc(ost, *s);
+			n++;
+		}
+		s++;
+	}
+}
diff --git a/source3/lib/cbuf.h b/source3/lib/cbuf.h
new file mode 100644
index 0000000000..ffb52d7b9a
--- /dev/null
+++ b/source3/lib/cbuf.h
@@ -0,0 +1,235 @@
+/*
+ * Samba Unix/Linux SMB client library
+ * Copyright (C) Gregor Beck 2010
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @file   cbuf.h
+ * @author Gregor Beck <gb@sernet.de>
+ * @date   Aug 2010
+ *
+ * @brief  A talloced character buffer.
+ *
+ * A cbuf carries a write position and keeps track of its size.
+ */
+
+#ifndef __CBUF_H
+#define __CBUF_H
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+
+struct cbuf;
+typedef struct cbuf cbuf;
+
+/**
+ * Create a new character buffer.
+ *
+ * @param talloc_ctx the talloc parent
+ *
+ * @return a new cbuf object, NULL on error
+ */
+cbuf* cbuf_new(const void* talloc_ctx);
+
+/**
+ * Create a copy of a character buffer.
+ *
+ * @param b the cbuf to copy
+ * @return a new cbuf object, NULL on error
+ */
+cbuf* cbuf_copy(const cbuf* b);
+
+/**
+ * Delete a character buffer.
+ * This invalidates b and free's the memory allocated.
+ * @warning don't talloc_free b directly, however freeing
+ *          the parent works as expected
+ * @param b the cbuf to delete
+ */
+void  cbuf_delete(cbuf* b);
+
+/**
+ * Reset the buffer to initial state.
+ * Set the write positon to the start of buffer, effectivly
+ * clearing its contents. Doesn't free memory.
+ *
+ * @param b the buffer to clear
+ *
+ * @return b
+ */
+cbuf* cbuf_clear(cbuf* b);
+
+/**
+ * Swap the contents of two buffers in O(1).
+ *
+ * @param b1 a character buffer
+ * @param b2 another character buffer
+ */
+void cbuf_swap(cbuf* b1, cbuf* b2);
+
+/**
+ * Swap the contents of a buffer with a talloced string.
+ *
+ * @param b a character buffer
+ * @param ptr a pointer to a talloced string
+ * @param len size of string, -1 means strlen(*ptr)
+ *
+ * @return b
+ */
+cbuf* cbuf_swapptr(cbuf* b, char** ptr, size_t len);
+
+/**
+ * Let a character buffer takeover the contents of another.
+ * This is equivalent to @code
+ *   cbuf_swap(b1, b2);
+ *   cbuf_delete(b2);
+ * @endcode
+ * @param b1 the destination
+ * @param b2 the victim
+ *
+ * @return b1
+ */
+cbuf* cbuf_takeover(cbuf* b1, cbuf* b2);
+
+/**
+ * Resize a character buffer.
+ * This may free allocated memory.
+ *
+ * @param b the character buffer.
+ * @param size the new size
+ *
+ * @return b, NULL on error
+ */
+cbuf* cbuf_resize(cbuf* b, size_t size);
+
+/**
+ * Reserve space in a character buffer.
+ * Assert there are at least len bytes following the current write position.
+ *
+ * @param b a character buffer
+ * @param len number of bytes to reserve.
+ *
+ * @return a pointer to the current write position, NULL on error
+ */
+char* cbuf_reserve(cbuf* b, size_t len);
+
+/**
+ * Put a character into the buffer.
+ *
+ * @param b a charcter buffer, may be NULL.
+ * @param c a character
+ * @return number of charcters written ((b==NULL) ? 0 : 1)
+ *
+ * @retval -1 on error
+ */
+int cbuf_putc(cbuf* b, char c);
+
+/**
+ * Put a string into the buffer.
+ *
+ * @param b a character buffer, may be NULL
+ * @param str a string
+ * @param len number of bytes to write, -1 means strlen(str)
+ *
+ * @return number of characters written, -1 on error
+ */
+int cbuf_puts(cbuf* b, const char* str, size_t len);
+
+/* /\** */
+/*  * Put a string into the buffer, changing case. */
+/*  * */
+/*  * @param b a character buffer, may be NULL */
+/*  * @param str a string */
+/*  * @param len number of bytes to write, -1 means strlen(str) */
+/*  * @param c   a character specifying case: */
+/*  *        @li 'U' upper case */
+/*  *        @li 'L' lower case */
+/*  *        @li 'T' title case */
+/*  *        @li 'P' preserve case */
+/*  * @return number of characters written, -1 on error */
+/*  *\/ */
+/* int cbuf_puts_case(cbuf* b, const char* str, size_t len, char c); */
+
+
+
+/**
+ * Put a uint32 into the buffer.
+ * Write in little endian order.
+ *
+ * @param b a character buffer, may be NULL
+ * @param u an uint32
+ *
+ * @return number of characters written, -1 on error
+ */
+int cbuf_putdw(cbuf* b, uint32_t u);
+
+/**
+ * Print formated to a character buffer.
+ *
+ * @param b a charcter buffer
+ * @param fmt a printf format string
+ *
+ * @return number of characters written, negative on error
+ */
+int cbuf_printf(cbuf* b, const char* fmt, ...);
+
+
+/**
+ * Get the current write position.
+ *
+ * @param b a character buffer.
+ *
+ * @return index of the next charcter to write.
+ */
+size_t cbuf_getpos(const cbuf* b);
+
+/**
+ * Set the current write position of a buffer.
+ * Invalidates the buffer contents from on the new position.
+ *
+ * @param b a charcter buffer
+ * @param pos a position obtained by cbuf_getpos
+ */
+void cbuf_setpos(cbuf* b, size_t pos);
+
+/**
+ * Get the buffer contents
+ * starting at idx.
+ * @pre @code idx <= cbuf_getpos(b) @endcode
+ * @param b a character buffer
+ * @param idx a position obtained by cbuf_getpos
+ *
+ * @return a NUL terminated string
+ */
+char* cbuf_gets(cbuf* b, size_t idx);
+
+/**
+ * Print quoted string to stream.
+ *
+ * @todo check for ssputc failure
+ * @see srprs_quoted_string
+ *
+ * @param[out] ost outstream
+ * @param[in]  s string
+ *
+ * @return numner of bytes written, -1 on error
+ */
+int cbuf_print_quoted_string(cbuf* ost, const char* s);
+
+
+#endif /*__CBUF_H*/