Lout 3.17.

git-svn-id: http://svn.savannah.nongnu.org/svn/lout/trunk@2 9365b830-b601-4143-9ba8-b4a8e2c3339c

1 files changed, 250 insertions, 0 deletions

diff --git a/z47.c b/z47.c
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+/*@z47.c:Environment Table:EnvReadRetrieve()@*********************************/
+/*                                                                           */
+/*  THE LOUT DOCUMENT FORMATTING SYSTEM (VERSION 3.17)                       */
+/*  COPYRIGHT (C) 1991, 1999 Jeffrey H. Kingston                             */
+/*                                                                           */
+/*  Jeffrey H. Kingston (jeff@cs.usyd.edu.au)                                */
+/*  Basser Department of Computer Science                                    */
+/*  The University of Sydney 2006                                            */
+/*  AUSTRALIA                                                                */
+/*                                                                           */
+/*  This program is free software; you can redistribute it and/or modify     */
+/*  it under the terms of the GNU General Public License as published by     */
+/*  the Free Software Foundation; either Version 2, or (at your option)      */
+/*  any later version.                                                       */
+/*                                                                           */
+/*  This program is distributed in the hope that it will be useful,          */
+/*  but WITHOUT ANY WARRANTY; without even the implied warranty of           */
+/*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            */
+/*  GNU General Public License for more details.                             */
+/*                                                                           */
+/*  You should have received a copy of the GNU General Public License        */
+/*  along with this program; if not, write to the Free Software              */
+/*  Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307 USA   */
+/*                                                                           */
+/*  FILE:         z47.c                                                      */
+/*  MODULE:       Environment Table                                          */
+/*  EXTERNS:      EnvInit(), EnvWriteRetrieve(), EnvWriteInsert(),           */
+/*                EnvReadRetrieve(), EnvReadInsert()                         */
+/*                                                                           */
+/*****************************************************************************/
+#include "externs.h"
+#define	TAB_SIZE	211
+#define	MAX_CACHE	180
+
+#define	env_offset(x)	back(x, ROWM)
+#define	env_lnum(x)	line_num(fpos(x))
+#define	env_fnum(x)	file_num(fpos(x))
+#define	env_read(x)	sized(x)
+
+static	OBJECT	env_cache;			/* cache of envts in use     */
+static	int	cache_count;			/* current size of cache     */
+static	int	stat_writes;			/* calls to WriteRetrieve    */
+static	int	stat_write_hits;		/* hits in WriteRetrieve     */
+static	int	stat_reads;			/* calls to ReadRetrieve     */
+static	int	stat_read_hits;			/* hits in ReadRetrieve      */
+
+static OBJECT tab[TAB_SIZE];
+
+#define hash1(pos, env, fnum)						\
+{									\
+  pos = ( (int) env + fnum ) % TAB_SIZE;				\
+}
+
+#define hash2(pos, fnum, offset)					\
+{									\
+  pos = ( offset + fnum ) % TAB_SIZE;					\
+}
+
+
+/*****************************************************************************/
+/*                                                                           */
+/*  void EnvInit(void)                                                       */
+/*                                                                           */
+/*  Initialize this module.                                                  */
+/*                                                                           */
+/*****************************************************************************/
+
+void EnvInit(void)
+{ int i;
+  debug0(DET, DD, "EnvInit()");
+  stat_reads = 0;
+  stat_read_hits = 0;
+  stat_writes = 0;
+  stat_write_hits = 0;
+  New(env_cache, ACAT);
+  cache_count = 0;
+  for( i = 0;  i < TAB_SIZE;  i++ )
+  { tab[i] = nilobj;
+  }
+  debug0(DET, DD, "EnvInit returning");
+} /* end EnvInit */
+
+
+/*****************************************************************************/
+/*                                                                           */
+/*  BOOLEAN EnvWriteRetrieve(OBJECT env, FILE_NUM fnum, int *offset, *lnum)  */
+/*                                                                           */
+/*  Return the offset in file fnum where environment env has been written,   */
+/*  or FALSE if env has not been written to this file.                       */
+/*                                                                           */
+/*****************************************************************************/
+
+BOOLEAN EnvWriteRetrieve(OBJECT env, FILE_NUM fnum, int *offset, int *lnum)
+{ int pos;  OBJECT link, y, z;
+  debug2(DET, DD, "EnvWriteRetrieve(env %d, %s)", (int) env, FileName(fnum));
+  debug1(DET, DDD, "  %s", EchoObject(env));
+  stat_writes++;
+  hash1(pos, env, fnum);
+  if( tab[pos] != nilobj )
+  {
+    for( link = Down(tab[pos]);  link != tab[pos];  link = NextDown(link) )
+    { Child(y, link);
+      Child(z, Down(y));
+      if( env_fnum(y) == fnum && z == env && !env_read(y) )
+      { MoveLink(LastUp(y), env_cache, PARENT);
+	*offset = env_offset(y);
+	*lnum   = env_lnum(y);
+	stat_write_hits++;
+	debug2(DET, DD, "EnvWriteRetrieve returning TRUE (offset %d, lnum %d)",
+	  *offset, *lnum);
+	return TRUE;
+      }
+    }
+  }
+  debug0(DET, DD, "EnvWriteRetrieve returning FALSE");
+  return FALSE;
+} /* end EnvWriteRetrieve */
+
+
+/*****************************************************************************/
+/*                                                                           */
+/*  void EnvWriteInsert(OBJECT env, FILE_NUM fnum, int offset, int lnum)     */
+/*                                                                           */
+/*  Record the fact that environment env has been written to file fnum       */
+/*  at the given offset.                                                     */
+/*                                                                           */
+/*****************************************************************************/
+
+void EnvWriteInsert(OBJECT env, FILE_NUM fnum, int offset, int lnum)
+{ int pos;  OBJECT loser, x;
+  debug3(DET, DD, "EnvWriteInsert(env %d, %s, %d)", (int) env,
+    FileName(fnum), offset);
+
+  /* to limit the cache size, remove least recently used entry if full */
+  if( cache_count >= MAX_CACHE )
+  {
+    Child(loser, Down(env_cache));
+    DeleteLink(Up(loser));
+    DisposeChild(Up(loser));
+    cache_count--;
+  }
+
+  /* insert the new entry */
+  hash1(pos, env, fnum);
+  if( tab[pos] == nilobj )  New(tab[pos], ACAT);
+  New(x, ACAT);
+  env_fnum(x) = fnum;
+  env_offset(x) = offset;
+  env_lnum(x) = lnum;
+  env_read(x) = FALSE;
+  Link(tab[pos], x);
+  Link(env_cache, x);
+  Link(x, env);
+  cache_count++;
+
+  debug1(DET, DD, "EnvWriteInsert returning (cache_count = %d)", cache_count);
+} /* end EnvWriteInsert */
+
+
+/*****************************************************************************/
+/*                                                                           */
+/*  BOOLEAN EnvReadRetrieve(FILE_NUM fnum, int offset, OBJECT *env)          */
+/*                                                                           */
+/*  Return the environment that appears in file fnum at the given offset,    */
+/*  or FALSE if this is not currently known.                                 */
+/*                                                                           */
+/*****************************************************************************/
+
+BOOLEAN EnvReadRetrieve(FILE_NUM fnum, int offset, OBJECT *env)
+{ int pos;  OBJECT link, y, z;
+  debug2(DET, DD, "EnvReadRetrieve(%s, %d)", FileName(fnum), offset);
+  stat_reads++;
+
+  hash2(pos, fnum, offset);
+  if( tab[pos] != nilobj )
+  {
+    for( link = Down(tab[pos]);  link != tab[pos];  link = NextDown(link) )
+    { Child(y, link);
+      Child(z, Down(y));
+      if( env_fnum(y) == fnum && env_offset(y) == offset && env_read(y) )
+      { MoveLink(LastUp(y), env_cache, PARENT);
+	Child(*env, Down(y));
+	stat_read_hits++;
+        debug1(DET, DD, "EnvReadRetrieve returning env %d", (int) *env);
+	  return TRUE;
+      }
+    }
+  }
+  debug0(DET, DD, "EnvReadRetrieve returning FALSE");
+  return FALSE;
+} /* end EnvReadRetrieve */
+
+
+/*****************************************************************************/
+/*                                                                           */
+/*  void EnvReadInsert(FILE_NUM fnum, int offset, OBJECT env)               */
+/*                                                                           */
+/*  Record the fact that environment env has just been read from file fnum   */
+/*  at position offset.                                                      */
+/*                                                                           */
+/*****************************************************************************/
+
+void EnvReadInsert(FILE_NUM fnum, int offset, OBJECT env)
+{ int pos; OBJECT x, loser;
+  debug3(DET, DD, "EnvReadInsert(%s, %d, env %d)",
+    FileName(fnum), offset, (int) env);
+
+  /* to limit the cache size, remove least recently used entry if full */
+  if( cache_count >= MAX_CACHE )
+  {
+    Child(loser, Down(env_cache));
+    DeleteLink(Up(loser));
+    DisposeChild(Up(loser));
+    cache_count--;
+  }
+
+  /* insert the new entry */
+  hash2(pos, fnum, offset);
+  if( tab[pos] == nilobj )  New(tab[pos], ACAT);
+  New(x, ACAT);
+  env_fnum(x) = fnum;
+  env_offset(x) = offset;
+  env_read(x) = TRUE;
+  Link(tab[pos], x);
+  Link(env_cache, x);
+  Link(x, env);
+  cache_count++;
+
+  debug1(DET, DD, "EnvReadInsert returning (cache_count = %d)", cache_count);
+} /* end EnvReadInsert */
+
+
+#if DEBUG_ON
+/*****************************************************************************/
+/*                                                                           */
+/*  void EnvDebug()                                                          */
+/*                                                                           */
+/*  Debug statistics of this module's performance.                           */
+/*                                                                           */
+/*****************************************************************************/
+
+void EnvDebug(void)
+{
+  debug3(DET, D, "Env Table  %6s %6s %6s", "calls", "hits", "% hits");
+  debug3(DET, D, "reading    %6d %6d %6.1f", stat_reads, stat_read_hits,
+  stat_reads == 0 ? (float) 0 : (float) 100 * stat_read_hits / stat_reads);
+  debug3(DET, D, "writing    %6d %6d %6.1f", stat_writes, stat_write_hits,
+  stat_writes == 0 ? (float) 0 : (float) 100 * stat_write_hits / stat_writes);
+} /* end EnvDebug */
+#endif