/*
* Sherlock Library -- Fast Buffered I/O
*
- * (c) 1997--2000 Martin Mares <mj@ucw.cz>
+ * (c) 1997--2004 Martin Mares <mj@ucw.cz>
+ * (c) 2004 Robert Spalek <robert@ucw.cz>
+ *
+ * This software may be freely distributed and used according to the terms
+ * of the GNU Lesser General Public License.
*/
#ifndef _SHERLOCK_FASTBUF_H
#include <stdio.h>
#endif
+#include <string.h>
+
+#include "lib/unaligned.h"
+
/*
- * Generic buffered I/O on a top of buffer swapping functions.
+ * Generic buffered I/O. You supply hooks to be called for low-level operations
+ * (swapping of buffers, seeking and closing), we do the rest.
*
* Buffer layout when reading:
*
*
* When writing:
*
- * +----------------+---------------------------+
- * | written data | free space |
- * +----------------+---------------------------+
- * ^ ^ ^
- * buffer=bstop bptr bufend
+ * +--------+--------------+--------------------+
+ * | unused | written data | free space |
+ * +--------+--------------+--------------------+
+ * ^ ^ ^ ^
+ * buffer bstop bptr bufend
+ *
+ * Dirty tricks:
+ *
+ * - You can mix reads and writes on the same stream, but you must
+ * call bflush() in between and remember that the file position
+ * points after the flushed buffer which is not necessarily the same
+ * 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 {
+ byte is_fastbuf[0]; /* Dummy field for checking of type casts */
byte *bptr, *bstop; /* Access pointers */
byte *buffer, *bufend; /* Start and end of the buffer */
byte *name; /* File name for error messages */
- uns buflen; /* Size of the buffer */
- sh_off_t pos; /* Position of buffer start in the file */
- sh_off_t fdpos; /* Current position in the non-buffered file */
- int fd; /* File descriptor, -1 if not a real file */
- int is_temp_file; /* Is a temporary file, delete on close */
- void *lldata; /* Data private to access functions below */
- void *llpos; /* ... continued ... */
+ sh_off_t pos; /* Position of bstop in the file */
int (*refill)(struct fastbuf *); /* Get a buffer with new data */
void (*spout)(struct fastbuf *); /* Write buffer data to the file */
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 */
+/* FastIO on standard files (specify buffer size 0 to enable mmaping) */
-struct fastbuf *bopen(byte *name, uns mode, uns buffer);
-struct fastbuf *bfdopen(int fd, uns buffer);
-void bbcopy(struct fastbuf *f, struct fastbuf *t, uns l);
+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);
/* FastIO on in-memory streams */
struct fastbuf *fbmem_create(unsigned blocksize); /* Create stream and return its writing fastbuf */
struct fastbuf *fbmem_clone_read(struct fastbuf *); /* Create reading fastbuf */
+/* FastIO on memory mapped files */
+
+struct fastbuf *bopen_mm(byte *name, uns mode);
+
+/* FastI on file descriptors with limit */
+
+struct fastbuf *bopen_limited_fd(int fd, uns bufsize, uns limit);
+
+/* FastIO on static buffers */
+
+void fbbuf_init_read(struct fastbuf *f, byte *buffer, uns size);
+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;
+}
+
+/* Configuring stream parameters */
+
+int bconfig(struct fastbuf *f, uns type, int data);
+
+#define BCONFIG_IS_TEMP_FILE 0
+
/* Universal functions working on all fastbuf's */
void bclose(struct fastbuf *f);
void bflush(struct fastbuf *f);
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);
+void bskip(struct fastbuf *f, uns len);
static inline sh_off_t btell(struct fastbuf *f)
{
- return f->pos + (f->bptr - f->buffer);
+ return f->pos + (f->bptr - f->bstop);
}
int bgetc_slow(struct fastbuf *f);
return (f->bptr < f->bstop) ? (int) *f->bptr : bpeekc_slow(f);
}
-static inline void bungetc(struct fastbuf *f, byte c)
+static inline void bungetc(struct fastbuf *f)
{
- *--f->bptr = c;
+ f->bptr--;
}
-void bputc_slow(struct fastbuf *f, byte c);
-static inline void bputc(struct fastbuf *f, byte c)
+void bputc_slow(struct fastbuf *f, uns c);
+static inline void bputc(struct fastbuf *f, uns c)
{
if (f->bptr < f->bufend)
*f->bptr++ = c;
bputc_slow(f, c);
}
-word bgetw_slow(struct fastbuf *f);
-static inline word bgetw(struct fastbuf *f)
+int bgetw_slow(struct fastbuf *f);
+static inline int bgetw(struct fastbuf *f)
{
- word w;
+ int w;
if (f->bptr + 2 <= f->bstop)
{
- byte *p = f->bptr;
-#ifdef CPU_CAN_DO_UNALIGNED_WORDS
- w = * ((word *) p);
-#else
-#ifdef CPU_BIG_ENDIAN
- w = (p[0] << 8) | p[1];
-#else
- w = (p[1] << 8) | p[0];
-#endif
-#endif
+ w = GET_U16(f->bptr);
f->bptr += 2;
return w;
}
u32 l;
if (f->bptr + 4 <= f->bstop)
{
- byte *p = f->bptr;
-#ifdef CPU_CAN_DO_UNALIGNED_LONGS
- l = * ((u32 *) p);
-#else
-#ifdef CPU_BIG_ENDIAN
- l = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
-#else
- l = (p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0];
-#endif
-#endif
+ l = GET_U32(f->bptr);
f->bptr += 4;
return l;
}
u64 bgetq_slow(struct fastbuf *f);
static inline u64 bgetq(struct fastbuf *f)
{
+ u64 l;
if (f->bptr + 8 <= f->bstop)
{
- u64 l;
- memcpy(&l, f->bptr, 8);
+ l = GET_U64(f->bptr);
f->bptr += 8;
return l;
}
u64 l;
if (f->bptr + 5 <= f->bstop)
{
- byte *p = f->bptr;
-#ifdef CPU_BIG_ENDIAN
- l = ((u64)p[0] << 32) | (u32)((p[1] << 24) | (p[2] << 16) | (p[3] << 8) | p[4]);
-#else
- l = ((u64)p[4] << 32) | (u32)((p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0]);
-#endif
+ l = GET_U40(f->bptr);
f->bptr += 5;
return l;
}
return bget5_slow(f);
}
-void bputw_slow(struct fastbuf *f, word w);
-static inline void bputw(struct fastbuf *f, word w)
+void bputw_slow(struct fastbuf *f, uns w);
+static inline void bputw(struct fastbuf *f, uns w)
{
if (f->bptr + 2 <= f->bufend)
{
- byte *p = f->bptr;
-#ifdef CPU_CAN_DO_UNALIGNED_WORDS
- * ((word *) p) = w;
-#else
-#ifdef CPU_BIG_ENDIAN
- p[0] = w >> 8U;
- p[1] = w;
-#else
- p[1] = w >> 8U;
- p[0] = w;
-#endif
-#endif
+ PUT_U16(f->bptr, w);
f->bptr += 2;
}
else
{
if (f->bptr + 4 <= f->bufend)
{
- byte *p = f->bptr;
-#ifdef CPU_CAN_DO_UNALIGNED_LONGS
- * ((u32 *) p) = l;
-#else
-#ifdef CPU_BIG_ENDIAN
- p[0] = l >> 24U;
- p[1] = l >> 16U;
- p[2] = l >> 8U;
- p[3] = l;
-#else
- p[3] = l >> 24U;
- p[2] = l >> 16U;
- p[1] = l >> 8U;
- p[0] = l;
-#endif
-#endif
+ PUT_U32(f->bptr, l);
f->bptr += 4;
}
else
{
if (f->bptr + 8 <= f->bufend)
{
- memcpy(f->bptr, &l, 8);
+ PUT_U64(f->bptr, l);
f->bptr += 8;
}
else
{
if (f->bptr + 5 <= f->bufend)
{
- byte *p = f->bptr;
- u32 low = l;
-#ifdef CPU_BIG_ENDIAN
- p[0] = l >> 32U;
- p[1] = low >> 24U;
- p[2] = low >> 16U;
- p[3] = low >> 8U;
- p[4] = low;
-#else
- p[4] = l >> 32U;
- p[3] = low >> 24U;
- p[2] = low >> 16U;
- p[1] = low >> 8U;
- p[0] = low;
-#endif
+ PUT_U40(f->bptr, l);
f->bptr += 5;
}
else
bput5_slow(f, l);
}
-uns bread_slow(struct fastbuf *f, void *b, uns l);
+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)
return l;
}
else
- return bread_slow(f, b, l);
+ return bread_slow(f, b, l, 0);
+}
+
+static inline uns breadb(struct fastbuf *f, void *b, uns l)
+{
+ if (f->bptr + l <= f->bstop)
+ {
+ memcpy(b, f->bptr, l);
+ f->bptr += l;
+ return l;
+ }
+ else
+ return bread_slow(f, b, l, 1);
}
void bwrite_slow(struct fastbuf *f, void *b, uns l);
}
byte *bgets(struct fastbuf *f, byte *b, uns l); /* Non-std */
+int bgets_nodie(struct fastbuf *f, byte *b, uns l);
+byte *bgets0(struct fastbuf *f, byte *b, uns l);
static inline void
bputs(struct fastbuf *f, byte *b)
bwrite(f, b, strlen(b));
}
+static inline void
+bputs0(struct fastbuf *f, byte *b)
+{
+ bwrite(f, b, strlen(b)+1);
+}
+
static inline void
bputsn(struct fastbuf *f, byte *b)
{
bputc(f, '\n');
}
-/* Direct I/O on buffers */
-
-int bdirect_read(struct fastbuf *f, byte **buf);
-int bdirect_write_prepare(struct fastbuf *f, byte **buf);
-void bdirect_write_commit(struct fastbuf *f, byte *pos);
+void bbcopy_slow(struct fastbuf *f, struct fastbuf *t, uns l);
+static inline void
+bbcopy(struct fastbuf *f, struct fastbuf *t, uns l)
+{
+ if (f->bptr + l <= f->bstop &&
+ t->bptr + l <= t->bufend)
+ {
+ memcpy(t->bptr, f->bptr, l);
+ t->bptr += l;
+ f->bptr += l;
+ }
+ else
+ bbcopy_slow(f, t, l);
+}
-/* Depending on compile-time configuration, we select the right function for reading/writing of file offsets */
+/* I/O on addr_int_t */
-#ifdef SHERLOCK_CONFIG_LARGE_DB
-#define bgeto(f) bget5(f)
-#define bputo(f,l) bput5(f,l)
-#define bgetp(f) bgetq(f)
-#define bputp(f,l) bputq(f,l)
+#ifdef CPU_64BIT_POINTERS
+#define bputa(x,p) bputq(x,p)
+#define bgeta(x) bgetq(x)
#else
-#define bgeto(f) bgetl(f)
-#define bputo(f,l) bputl(f,l)
-#define bgetp(f) bgetl(f)
-#define bputp(f,l) bputl(f,l)
+#define bputa(x,p) bputl(x,p)
+#define bgeta(x) bgetl(x)
#endif
+/* Direct I/O on buffers */
+
+static inline uns
+bdirect_read_prepare(struct fastbuf *f, byte **buf)
+{
+ if (f->bptr == f->bstop && !f->refill(f))
+ return 0;
+ *buf = f->bptr;
+ return f->bstop - f->bptr;
+}
+
+static inline void
+bdirect_read_commit(struct fastbuf *f, byte *pos)
+{
+ 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;
+}
+
+static inline void
+bdirect_write_commit(struct fastbuf *f, byte *pos)
+{
+ f->bptr = pos;
+}
+
+/* Formatted output */
+
+int bprintf(struct fastbuf *b, byte *msg, ...);
+int vbprintf(struct fastbuf *b, byte *msg, va_list args);
+
#endif
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