X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Ffastbuf.h;h=800794c7ae5669790d5d98eb94468196a38c3892;hb=3e1e48b786ff2295ca6196253849b48d3a7f91b9;hp=1f502ce5d733a7ac85d95e7abbd20be2446a1a02;hpb=2a5686e35c9d6be6cefe22d49cfff6d23ec2e842;p=libucw.git

diff --git a/lib/fastbuf.h b/lib/fastbuf.h
index 1f502ce5..800794c7 100644
--- a/lib/fastbuf.h
+++ b/lib/fastbuf.h
@@ -1,14 +1,15 @@
 /*
- *	Sherlock Library -- Fast Buffered I/O
+ *	UCW Library -- Fast Buffered I/O
  *
- *	(c) 1997--2002 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
-#define _SHERLOCK_FASTBUF_H
+#ifndef _UCW_FASTBUF_H
+#define _UCW_FASTBUF_H
 
 #ifndef EOF
 #include <stdio.h>
@@ -50,6 +51,17 @@
  *	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 {
@@ -62,34 +74,55 @@ struct fastbuf {
   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 fb_file {
-  struct fastbuf fb;
-  int fd;				/* File descriptor, -1 if not a real file */
-  int is_temp_file;			/* 0=normal file, 1=temporary file, delete on close, -1=shared FD */
-};
-#define FB_FILE(f) ((struct fb_file *)(f)->is_fastbuf)
-
-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);
-#define FB_IS_TEMP_FILE(f) FB_FILE(f)->is_temp_file
+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 */
 
 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, 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;
+}
+
+/* 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);
+sh_off_t bfilesize(struct fastbuf *f);
 
 static inline sh_off_t btell(struct fastbuf *f)
 {
@@ -122,11 +155,23 @@ static inline void bputc(struct fastbuf *f, uns c)
     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;
@@ -140,7 +185,7 @@ u32 bgetl_slow(struct fastbuf *f);
 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;
@@ -154,7 +199,7 @@ u64 bgetq_slow(struct fastbuf *f);
 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;
@@ -168,7 +213,7 @@ u64 bget5_slow(struct fastbuf *f);
 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;
@@ -181,7 +226,7 @@ static inline u64 bget5(struct fastbuf *f)
 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;
@@ -193,7 +238,7 @@ static inline void bputw(struct fastbuf *f, uns w)
 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;
@@ -205,7 +250,7 @@ static inline void bputl(struct fastbuf *f, u32 l)
 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;
@@ -217,7 +262,7 @@ static inline void bputq(struct fastbuf *f, u64 l)
 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;
@@ -229,7 +274,7 @@ static inline void bput5(struct fastbuf *f, u64 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)
+  if (bavailr(f) >= l)
     {
       memcpy(b, f->bptr, l);
       f->bptr += l;
@@ -241,7 +286,7 @@ static inline uns bread(struct fastbuf *f, void *b, uns 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;
@@ -254,7 +299,7 @@ static inline uns breadb(struct fastbuf *f, void *b, uns 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;
@@ -264,6 +309,7 @@ static inline void bwrite(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
@@ -289,8 +335,7 @@ 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)
+  if (bavailr(f) >= l && bavailw(t) >= l)
     {
       memcpy(t->bptr, f->bptr, l);
       t->bptr += l;
@@ -300,6 +345,18 @@ bbcopy(struct fastbuf *f, struct fastbuf *t, uns 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
@@ -312,13 +369,13 @@ bbcopy(struct fastbuf *f, struct fastbuf *t, uns l)
 
 /* Direct I/O on buffers */
 
-static inline int
+static inline uns
 bdirect_read_prepare(struct fastbuf *f, byte **buf)
 {
   if (f->bptr == f->bstop && !f->refill(f))
-    return EOF;
+    return 0;
   *buf = f->bptr;
-  return f->bstop - f->bptr;
+  return bavailr(f);
 }
 
 static inline void
@@ -327,13 +384,20 @@ bdirect_read_commit(struct fastbuf *f, byte *pos)
   f->bptr = pos;
 }
 
-static inline int
+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
@@ -342,4 +406,9 @@ 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