segment lib: code cleanup and optimization

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@45869 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/segment/format.c

@@ -12,12 +12,12 @@
  * \date 2005-2009
  */
 
-#include <grass/config.h>
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
 #include <limits.h>
+#include <grass/gis.h>
 #include <grass/segment.h>
 
 
@@ -169,7 +169,7 @@ static int write_int(int fd, int n)
 static int zero_fill(int fd, off_t nbytes)
 {
 #ifndef USE_LSEEK
-    char buf[10240];
+    char buf[16384];
     register char *b;
     register int n;
 

lib/segment/get_row.c

@@ -16,6 +16,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
+#include <grass/gis.h>
 #include <grass/segment.h>
 
 

lib/segment/init.c

@@ -21,6 +21,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
+#include <grass/gis.h>
 #include <grass/segment.h>
 
 

lib/segment/pagein.c

@@ -16,8 +16,8 @@
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
+#include <grass/gis.h>
 #include <grass/segment.h>
-#include <grass/rbtree.h>
 
 
 /**
@@ -38,18 +38,15 @@ int segment_pagein(SEGMENT * SEG, int n)
 {
     int cur;
     int read_result;
-    SEGID *seg_found, seg_search;
 
     /* is n the current segment? */
     if (n == SEG->scb[SEG->cur].n)
 	return SEG->cur;
 
-    /* search the in memory segments */
-    seg_search.i = 0;
-    seg_search.n = n;
-    seg_found = rbtree_find(SEG->loaded, &seg_search);
-    if (seg_found) {
-	cur = seg_found->i;
+    /* segment n is in memory ? */
+
+    if (SEG->load_idx[n] >= 0) {
+	cur = SEG->load_idx[n];
 
 	if (SEG->scb[cur].age != SEG->youngest) {
 	    /* splice out */
@@ -74,12 +71,9 @@ int segment_pagein(SEGMENT * SEG, int n)
 	cur = SEG->oldest->cur;
 	SEG->oldest->cur = -1;
 
-	/* unload segment (remove from search tree) */
+	/* unload segment */
 	if (SEG->scb[cur].n >= 0) {
-	    seg_search.n = SEG->scb[cur].n;
-	    if (rbtree_remove(SEG->loaded, &seg_search) == 0)
-		G_fatal_error("could not remove segment");
-	    seg_search.n = n;
+	    SEG->load_idx[SEG->scb[cur].n] = -1;
 
 	    /* write it out if dirty */
 	    if (SEG->scb[cur].dirty) {
@@ -115,10 +109,8 @@ int segment_pagein(SEGMENT * SEG, int n)
 	return -1;
     }
 
-    /* remember loaded segment */
-    seg_search.i = cur;
-    if (rbtree_insert(SEG->loaded, &seg_search) == 0)
-	G_fatal_error("could not insert segment");
+    /* add loaded segment to index */
+    SEG->load_idx[n] = cur;
 
     /* make it youngest segment */
     SEG->youngest = SEG->youngest->younger;

lib/segment/pageout.c

@@ -16,6 +16,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
+#include <grass/gis.h>
 #include <grass/segment.h>
 
 

lib/segment/put.c

@@ -13,6 +13,7 @@
  */
 
 #include <string.h>
+#include <grass/gis.h>
 #include <grass/segment.h>
 
 

lib/segment/put_row.c

@@ -16,8 +16,8 @@
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
-#include <grass/segment.h>
 #include <grass/gis.h>
+#include <grass/segment.h>
 
 
 /*      buf is CELL *   WRAT code       */

lib/segment/release.c

@@ -13,8 +13,8 @@
  */
 
 #include <stdlib.h>
+#include <grass/gis.h>
 #include <grass/segment.h>
-#include <grass/rbtree.h>
 
 
 /**
@@ -30,7 +30,7 @@
  *
  * \param[in,out] seg
  * \return 1 if successful
- * \return -1 if segment is not available (not open)
+ * \return -1 if SEGMENT is not available (not open)
  */
 
 int segment_release(SEGMENT * SEG)
@@ -41,12 +41,12 @@ int segment_release(SEGMENT * SEG)
 	return -1;
 
     for (i = 0; i < SEG->nseg; i++)
-	free(SEG->scb[i].buf);
-    free(SEG->scb);
+	G_free(SEG->scb[i].buf);
+    G_free(SEG->scb);
 
-    free(SEG->freeslot);
-    free(SEG->agequeue);
-    rbtree_destroy(SEG->loaded);
+    G_free(SEG->freeslot);
+    G_free(SEG->agequeue);
+    G_free(SEG->load_idx);
 
     SEG->open = 0;
 

lib/segment/seek.c

@@ -12,7 +12,6 @@
  * \date 2005-2009
  */
 
-#include <grass/config.h>
 #include <stdio.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -48,9 +47,7 @@ int segment_seek_fast(const SEGMENT * SEG, int n, int index)
 
 int segment_seek_slow(const SEGMENT * SEG, int n, int index)
 {
-    off_t offset;
-
-    offset = (off_t) n * SEG->size + index + SEG->offset;
+    off_t offset = (off_t) n * SEG->size + index + SEG->offset;
 
     if (lseek(SEG->fd, offset, SEEK_SET) == (off_t) - 1) {
 	G_warning("segment_seek: %s", strerror(errno));

lib/segment/setup.c

@@ -17,7 +17,6 @@
 #include <math.h>
 #include <grass/gis.h>
 #include <grass/segment.h>
-#include <grass/rbtree.h>
 
 
 /**
@@ -37,7 +36,7 @@
 int segment_setup(SEGMENT * SEG)
 {
     int i;
-    int seg_exp;
+    int seg_exp, n_total_segs;
 
     SEG->open = 0;
 
@@ -90,11 +89,11 @@ int segment_setup(SEGMENT * SEG)
     }
 
     /* adjust number of open segments if larger than number of total segments */
-    if (SEG->nseg > SEG->spr * ((SEG->nrows + SEG->srows - 1) / SEG->srows)) {
+    n_total_segs = SEG->spr * ((SEG->nrows + SEG->srows - 1) / SEG->srows);
+    if (SEG->nseg > n_total_segs) {
 	G_debug(1, "segment: reducing number of open segments from %d to %d",
-		  SEG->nseg,
-		  SEG->spr * ((SEG->nrows + SEG->srows - 1) / SEG->srows));
-	SEG->nseg = SEG->spr * ((SEG->nrows + SEG->srows - 1) / SEG->srows);
+		  SEG->nseg, n_total_segs);
+	SEG->nseg = n_total_segs;
     }
 
     if ((SEG->scb =
@@ -140,25 +139,15 @@ int segment_setup(SEGMENT * SEG)
     SEG->cur = 0;
     SEG->open = 1;
 
-    SEG->loaded = rbtree_create(segment_compare, sizeof(SEGID));
+    /* SEG->loaded = rbtree_create(segment_compare, sizeof(SEGID)); */
+    /* SEG->loaded = NULL; */
+    
+    /* index for each segment, same like cache of r.proj  */
+    SEG->load_idx = G_malloc(n_total_segs * sizeof(int));
 
-    return 1;
-}
-
-int segment_compare(const void *sega, const void *segb)
-{
-    SEGID *a = (SEGID *) sega;
-    SEGID *b = (SEGID *) segb;
-
-    return a->n < b->n ? -1 : (a->n > b->n);
+    for (i = 0; i < n_total_segs; i++)
+	SEG->load_idx[i] = -1;
+    
 
-    /* short version of
-
-    if (a->n > b->n)
-	return 1;
-    else if (a->n < b->n)
-	return -1;
-
-    return 0;
-    */
+    return 1;
 }