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-rw-r--r--contrib/less/ch.c106
1 files changed, 82 insertions, 24 deletions
diff --git a/contrib/less/ch.c b/contrib/less/ch.c
index ad85be049401..3aaa1525faf4 100644
--- a/contrib/less/ch.c
+++ b/contrib/less/ch.c
@@ -21,6 +21,8 @@
#include <windows.h>
#endif
+typedef POSITION BLOCKNUM;
+
public int ignore_eoi;
/*
@@ -29,34 +31,38 @@ public int ignore_eoi;
* in order from most- to least-recently used.
* The circular list is anchored by the file state "thisfile".
*/
-#define LBUFSIZE 1024
+#define LBUFSIZE 8192
struct buf {
- struct buf *next, *prev; /* Must be first to match struct filestate */
- long block;
+ struct buf *next, *prev;
+ struct buf *hnext, *hprev;
+ BLOCKNUM block;
unsigned int datasize;
unsigned char data[LBUFSIZE];
};
+struct buflist {
+ /* -- Following members must match struct buf */
+ struct buf *buf_next, *buf_prev;
+ struct buf *buf_hnext, *buf_hprev;
+};
+
/*
* The file state is maintained in a filestate structure.
* A pointer to the filestate is kept in the ifile structure.
*/
+#define BUFHASH_SIZE 64
struct filestate {
- /* -- Following members must match struct buf */
struct buf *buf_next, *buf_prev;
- long buf_block;
- /* -- End of struct buf copy */
+ struct buflist hashtbl[BUFHASH_SIZE];
int file;
int flags;
POSITION fpos;
int nbufs;
- long block;
+ BLOCKNUM block;
unsigned int offset;
POSITION fsize;
};
-
-#define END_OF_CHAIN ((struct buf *)thisfile)
#define ch_bufhead thisfile->buf_next
#define ch_buftail thisfile->buf_prev
#define ch_nbufs thisfile->nbufs
@@ -67,6 +73,24 @@ struct filestate {
#define ch_flags thisfile->flags
#define ch_file thisfile->file
+#define END_OF_CHAIN ((struct buf *)&thisfile->buf_next)
+#define END_OF_HCHAIN(h) ((struct buf *)&thisfile->hashtbl[h])
+#define BUFHASH(blk) ((blk) & (BUFHASH_SIZE-1))
+
+#define FOR_BUFS_IN_CHAIN(h,bp) \
+ for (bp = thisfile->hashtbl[h].buf_hnext; \
+ bp != END_OF_HCHAIN(h); bp = bp->hnext)
+
+#define HASH_RM(bp) \
+ (bp)->hnext->hprev = (bp)->hprev; \
+ (bp)->hprev->hnext = (bp)->hnext;
+
+#define HASH_INS(bp,h) \
+ (bp)->hnext = thisfile->hashtbl[h].buf_hnext; \
+ (bp)->hprev = END_OF_HCHAIN(h); \
+ thisfile->hashtbl[h].buf_hnext->hprev = (bp); \
+ thisfile->hashtbl[h].buf_hnext = (bp);
+
static struct filestate *thisfile;
static int ch_ungotchar = -1;
@@ -100,6 +124,7 @@ fch_get()
register struct buf *bp;
register int n;
register int slept;
+ register int h;
POSITION pos;
POSITION len;
@@ -108,7 +133,9 @@ fch_get()
/*
* Look for a buffer holding the desired block.
*/
- for (bp = ch_bufhead; bp != END_OF_CHAIN; bp = bp->next)
+ h = BUFHASH(ch_block);
+ FOR_BUFS_IN_CHAIN(h, bp)
+ {
if (bp->block == ch_block)
{
if (ch_offset >= bp->datasize)
@@ -118,6 +145,7 @@ fch_get()
goto read_more;
goto found;
}
+ }
/*
* Block is not in a buffer.
* Take the least recently used buffer
@@ -125,7 +153,7 @@ fch_get()
* If the LRU buffer has data in it,
* then maybe allocate a new buffer.
*/
- if (ch_buftail == END_OF_CHAIN || ch_buftail->block != (long)(-1))
+ if (ch_buftail == END_OF_CHAIN || ch_buftail->block != -1)
{
/*
* There is no empty buffer to use.
@@ -142,8 +170,10 @@ fch_get()
autobuf = OPT_OFF;
}
bp = ch_buftail;
+ HASH_RM(bp); /* Remove from old hash chain. */
bp->block = ch_block;
bp->datasize = 0;
+ HASH_INS(bp, h); /* Insert into new hash chain. */
read_more:
pos = (ch_block * LBUFSIZE) + bp->datasize;
@@ -230,7 +260,11 @@ fch_get()
* Wait a while, then try again.
*/
if (!slept)
- ierror("Waiting for data", NULL_PARG);
+ {
+ PARG parg;
+ parg.p_string = wait_message();
+ ierror("%s", &parg);
+ }
#if !MSDOS_COMPILER
sleep(1);
#else
@@ -253,11 +287,16 @@ fch_get()
*/
bp->next->prev = bp->prev;
bp->prev->next = bp->next;
-
bp->next = ch_bufhead;
bp->prev = END_OF_CHAIN;
ch_bufhead->prev = bp;
ch_bufhead = bp;
+
+ /*
+ * Move to head of hash chain too.
+ */
+ HASH_RM(bp);
+ HASH_INS(bp, h);
}
if (ch_offset >= bp->datasize)
@@ -318,8 +357,8 @@ sync_logfile()
{
register struct buf *bp;
int warned = FALSE;
- long block;
- long nblocks;
+ BLOCKNUM block;
+ BLOCKNUM nblocks;
nblocks = (ch_fpos + LBUFSIZE - 1) / LBUFSIZE;
for (block = 0; block < nblocks; block++)
@@ -352,13 +391,17 @@ sync_logfile()
*/
static int
buffered(block)
- long block;
+ BLOCKNUM block;
{
register struct buf *bp;
+ register int h;
- for (bp = ch_bufhead; bp != END_OF_CHAIN; bp = bp->next)
+ h = BUFHASH(block);
+ FOR_BUFS_IN_CHAIN(h, bp)
+ {
if (bp->block == block)
return (TRUE);
+ }
return (FALSE);
}
@@ -370,7 +413,7 @@ buffered(block)
ch_seek(pos)
register POSITION pos;
{
- long new_block;
+ BLOCKNUM new_block;
POSITION len;
len = ch_length();
@@ -470,12 +513,10 @@ ch_length()
/*
* Return the current position in the file.
*/
-#define tellpos(blk,off) ((POSITION)((((long)(blk)) * LBUFSIZE) + (off)))
-
public POSITION
ch_tell()
{
- return (tellpos(ch_block, ch_offset));
+ return (ch_block * LBUFSIZE) + ch_offset;
}
/*
@@ -570,7 +611,7 @@ ch_flush()
* Initialize all the buffers.
*/
for (bp = ch_bufhead; bp != END_OF_CHAIN; bp = bp->next)
- bp->block = (long)(-1);
+ bp->block = -1;
/*
* Figure out the size of the file, if we can.
@@ -626,15 +667,31 @@ ch_addbuf()
if (bp == NULL)
return (1);
ch_nbufs++;
- bp->block = (long)(-1);
+ bp->block = -1;
bp->next = END_OF_CHAIN;
bp->prev = ch_buftail;
ch_buftail->next = bp;
ch_buftail = bp;
+ HASH_INS(bp, 0);
return (0);
}
/*
+ *
+ */
+ static void
+init_hashtbl()
+{
+ register int h;
+
+ for (h = 0; h < BUFHASH_SIZE; h++)
+ {
+ thisfile->hashtbl[h].buf_hnext = END_OF_HCHAIN(h);
+ thisfile->hashtbl[h].buf_hprev = END_OF_HCHAIN(h);
+ }
+}
+
+/*
* Delete all buffers for this file.
*/
static void
@@ -650,6 +707,7 @@ ch_delbufs()
free(bp);
}
ch_nbufs = 0;
+ init_hashtbl();
}
/*
@@ -693,7 +751,6 @@ ch_init(f, flags)
thisfile = (struct filestate *)
calloc(1, sizeof(struct filestate));
thisfile->buf_next = thisfile->buf_prev = END_OF_CHAIN;
- thisfile->buf_block = (long)(-1);
thisfile->nbufs = 0;
thisfile->flags = 0;
thisfile->fpos = 0;
@@ -702,6 +759,7 @@ ch_init(f, flags)
thisfile->file = -1;
thisfile->fsize = NULL_POSITION;
ch_flags = flags;
+ init_hashtbl();
/*
* Try to seek; set CH_CANSEEK if it works.
*/
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-18 02:42:01 +0000