/*
- * Sherlock Library -- Fast Buffered I/O
+ * UCW Library -- Fast Buffered I/O
*
* (c) 1997--2004 Martin Mares <mj@ucw.cz>
* (c) 2004 Robert Spalek <robert@ucw.cz>
* of the GNU Lesser General Public License.
*/
-#ifndef _SHERLOCK_FASTBUF_H
-#define _SHERLOCK_FASTBUF_H
+#ifndef _UCW_FASTBUF_H
+#define _UCW_FASTBUF_H
#ifndef EOF
#include <stdio.h>
* as after the data you've read.
* - The spout/refill hooks can change not only bptr and bstop, but also
* the location of the buffer; fb-mem.c takes advantage of it.
+ * - In some cases, the user of the bdirect interface can be allowed to modify
+ * the data in the buffer to avoid unnecessary copying. If the back-end
+ * allows such modifications, it can set can_overwrite_buffer accordingly:
+ * * 0 if no modification is allowed,
+ * * 1 if the user can modify the buffer on the condition that
+ * the modifications will be undone before calling the next
+ * fastbuf operation
+ * * 2 if the user is allowed to overwrite the data in the buffer
+ * if bdirect_read_commit_modified() is called afterwards.
+ * In this case, the back-end must be prepared for trimming
+ * of the buffer which is done by the commit function.
*/
struct fastbuf {
void (*seek)(struct fastbuf *, sh_off_t, int); /* Slow path for bseek(), buffer already flushed */
void (*close)(struct fastbuf *); /* Close the stream */
int (*config)(struct fastbuf *, uns, int); /* Configure the stream */
+ int can_overwrite_buffer; /* Can the buffer be altered? (see discussion above) 0=never, 1=temporarily, 2=permanently */
};
/* FastIO on standard files (specify buffer size 0 to enable mmaping) */
-struct fastbuf *bopen(byte *name, uns mode, uns buffer);
-struct fastbuf *bopen_tmp(uns buffer);
-struct fastbuf *bfdopen(int fd, uns buffer);
-struct fastbuf *bfdopen_shared(int fd, uns buffer);
+struct fastbuf *bopen(byte *name, uns mode, uns buflen);
+struct fastbuf *bopen_tmp(uns buflen);
+struct fastbuf *bfdopen(int fd, uns buflen);
+struct fastbuf *bfdopen_shared(int fd, uns buflen);
+void bfilesync(struct fastbuf *b);
/* FastIO on in-memory streams */
/* FastIO on static buffers */
-void fbbuf_init_read(struct fastbuf *f, byte *buffer, uns size);
+void fbbuf_init_read(struct fastbuf *f, byte *buffer, uns size, uns can_overwrite);
void fbbuf_init_write(struct fastbuf *f, byte *buffer, uns size);
static inline uns
fbbuf_count_written(struct fastbuf *f)
return f->bptr - f->bstop;
}
+/* FastIO on recyclable growing buffers */
+
+struct fastbuf *fbgrow_create(unsigned basic_size);
+void fbgrow_reset(struct fastbuf *b); /* Reset stream and prepare for writing */
+void fbgrow_rewind(struct fastbuf *b); /* Prepare for reading */
+
/* Configuring stream parameters */
int bconfig(struct fastbuf *f, uns type, int data);
#define BCONFIG_IS_TEMP_FILE 0
-#define BCONFIG_CAN_OVERWRITE 1
- /* Specifies whether the caller is allowed to perform the following optimized
- * 0-copy write operation:
- * - get the buffer by bdirect_read_prepare()
- * - modify the buffer, e.g. by putting \0's inside
- * - call bflush() to let the fastbuf know
- * Values:
- * 0: read-only memory
- * 1: you can write into read-write memory, if you restore the original value
- * 2: you can rewrite the original content */
/* Universal functions working on all fastbuf's */
void bseek(struct fastbuf *f, sh_off_t pos, int whence);
void bsetpos(struct fastbuf *f, sh_off_t pos);
void brewind(struct fastbuf *f);
+sh_off_t bfilesize(struct fastbuf *f);
static inline sh_off_t btell(struct fastbuf *f)
{
bputc_slow(f, c);
}
+static inline uns
+bavailr(struct fastbuf *f)
+{
+ return f->bstop - f->bptr;
+}
+
+static inline uns
+bavailw(struct fastbuf *f)
+{
+ return f->bufend - f->bptr;
+}
+
int bgetw_slow(struct fastbuf *f);
static inline int bgetw(struct fastbuf *f)
{
int w;
- if (f->bptr + 2 <= f->bstop)
+ if (bavailr(f) >= 2)
{
w = GET_U16(f->bptr);
f->bptr += 2;
static inline u32 bgetl(struct fastbuf *f)
{
u32 l;
- if (f->bptr + 4 <= f->bstop)
+ if (bavailr(f) >= 4)
{
l = GET_U32(f->bptr);
f->bptr += 4;
static inline u64 bgetq(struct fastbuf *f)
{
u64 l;
- if (f->bptr + 8 <= f->bstop)
+ if (bavailr(f) >= 8)
{
l = GET_U64(f->bptr);
f->bptr += 8;
static inline u64 bget5(struct fastbuf *f)
{
u64 l;
- if (f->bptr + 5 <= f->bstop)
+ if (bavailr(f) >= 5)
{
l = GET_U40(f->bptr);
f->bptr += 5;
void bputw_slow(struct fastbuf *f, uns w);
static inline void bputw(struct fastbuf *f, uns w)
{
- if (f->bptr + 2 <= f->bufend)
+ if (bavailw(f) >= 2)
{
PUT_U16(f->bptr, w);
f->bptr += 2;
void bputl_slow(struct fastbuf *f, u32 l);
static inline void bputl(struct fastbuf *f, u32 l)
{
- if (f->bptr + 4 <= f->bufend)
+ if (bavailw(f) >= 4)
{
PUT_U32(f->bptr, l);
f->bptr += 4;
void bputq_slow(struct fastbuf *f, u64 l);
static inline void bputq(struct fastbuf *f, u64 l)
{
- if (f->bptr + 8 <= f->bufend)
+ if (bavailw(f) >= 8)
{
PUT_U64(f->bptr, l);
f->bptr += 8;
void bput5_slow(struct fastbuf *f, u64 l);
static inline void bput5(struct fastbuf *f, u64 l)
{
- if (f->bptr + 5 <= f->bufend)
+ if (bavailw(f) >= 5)
{
PUT_U40(f->bptr, l);
f->bptr += 5;
uns bread_slow(struct fastbuf *f, void *b, uns l, uns check);
static inline uns bread(struct fastbuf *f, void *b, uns l)
{
- if (f->bptr + l <= f->bstop)
+ if (bavailr(f) >= l)
{
memcpy(b, f->bptr, l);
f->bptr += l;
static inline uns breadb(struct fastbuf *f, void *b, uns l)
{
- if (f->bptr + l <= f->bstop)
+ if (bavailr(f) >= l)
{
memcpy(b, f->bptr, l);
f->bptr += l;
void bwrite_slow(struct fastbuf *f, void *b, uns l);
static inline void bwrite(struct fastbuf *f, void *b, uns l)
{
- if (f->bptr + l <= f->bufend)
+ if (bavailw(f) >= l)
{
memcpy(f->bptr, b, l);
f->bptr += l;
static inline void
bbcopy(struct fastbuf *f, struct fastbuf *t, uns l)
{
- if (f->bptr + l <= f->bstop &&
- t->bptr + l <= t->bufend)
+ if (bavailr(f) >= l && bavailw(t) >= l)
{
memcpy(t->bptr, f->bptr, l);
t->bptr += l;
bbcopy_slow(f, t, l);
}
+int bskip_slow(struct fastbuf *f, uns len);
+static inline int bskip(struct fastbuf *f, uns len)
+{
+ if (bavailr(f) >= len)
+ {
+ f->bptr += len;
+ return 1;
+ }
+ else
+ return bskip_slow(f, len);
+}
+
/* I/O on addr_int_t */
#ifdef CPU_64BIT_POINTERS
bdirect_read_prepare(struct fastbuf *f, byte **buf)
{
if (f->bptr == f->bstop && !f->refill(f))
- return 0;
+ {
+ *buf = NULL; // This is not needed, but it helps to get rid of spurious warnings
+ return 0;
+ }
*buf = f->bptr;
- return f->bstop - f->bptr;
+ return bavailr(f);
}
static inline void
f->bptr = pos;
}
+static inline void
+bdirect_read_commit_modified(struct fastbuf *f, byte *pos)
+{
+ f->bptr = pos;
+ f->buffer = pos; /* Avoid seeking backwards in the buffer */
+}
+
static inline uns
bdirect_write_prepare(struct fastbuf *f, byte **buf)
{
if (f->bptr == f->bufend)
f->spout(f);
*buf = f->bptr;
- return f->bufend - f->bptr;
+ return bavailw(f);
}
static inline void
/* Formatted output */
-int bprintf(struct fastbuf *b, byte *msg, ...);
-int vbprintf(struct fastbuf *b, byte *msg, va_list args);
+int bprintf(struct fastbuf *b, char *msg, ...) FORMAT_CHECK(printf,2,3);
+int vbprintf(struct fastbuf *b, char *msg, va_list args);
#endif