From 03b47b3e34823b774c2648282ac94085eec3deb5 Mon Sep 17 00:00:00 2001
From: Krzysztof Blaszkowski <kb@sysmikro.com.pl>
Date: Thu, 7 Jan 2016 08:54:14 +0100
Subject: [PATCH] src/frontend/outif.c, plotAddRealValue() etc, rallocate more
 coarsely

reallocate in chunks, instead of once per time step.
---
 src/frontend/dvec.c        | 14 ++++++++++++++
 src/frontend/outitf.c      | 28 ++++++++++++++++++++++++----
 src/include/ngspice/dvec.h |  2 ++
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/src/frontend/dvec.c b/src/frontend/dvec.c
index 54f4efab8..6da1d44a3 100644
--- a/src/frontend/dvec.c
+++ b/src/frontend/dvec.c
@@ -16,6 +16,7 @@ dvec_alloc(char *name, int type, short flags, int length, void *storage)
     rv->v_type = type;
     rv->v_flags = flags;
     rv->v_length = length;
+    rv->v_alloc_length = length;
 
     if (!length) {
         rv->v_realdata = NULL;
@@ -60,6 +61,19 @@ dvec_realloc(struct dvec *v, int length, void *storage)
     }
 
     v->v_length = length;
+    v->v_alloc_length = length;
+}
+
+
+void
+dvec_extend(struct dvec *v, int length)
+{
+    if (isreal(v))
+        v->v_realdata = TREALLOC(double, v->v_realdata, length);
+    else
+        v->v_compdata = TREALLOC(ngcomplex_t, v->v_compdata, length);
+
+    v->v_alloc_length = length;
 }
 
 
diff --git a/src/frontend/outitf.c b/src/frontend/outitf.c
index ba8372b91..f965a252c 100644
--- a/src/frontend/outitf.c
+++ b/src/frontend/outitf.c
@@ -1,7 +1,7 @@
 /**********
 Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1988 Wayne A. Christopher, U. C. Berkeley CAD Group
-Modified: 2000 AlansFixes
+Modified: 2000 AlansFixes, 2013/2015 patch by Krzysztof Blaszkowski
 **********/
 
 /*
@@ -1057,17 +1057,35 @@ plotInit(runDesc *run)
 }
 
 
+static inline int
+vlength2delta(int l)
+{
+    if (l < 50000)
+        return 512;
+    if (l < 200000)
+        return 256;
+    if (l < 500000)
+        return 128;
+    /* larger memory allocations may exhaust memory easily
+     * this function may use better estimation depending on
+     * available memory and number of vectors (run->numData)
+     */
+    return 64;
+}
+
+
 static void
 plotAddRealValue(dataDesc *desc, double value)
 {
     struct dvec *v = desc->vec;
 
+    if (v->v_length >= v->v_alloc_length)
+        dvec_extend(v, v->v_length + vlength2delta(v->v_length));
+
     if (isreal(v)) {
-        v->v_realdata = TREALLOC(double, v->v_realdata, v->v_length + 1);
         v->v_realdata[v->v_length] = value;
     } else {
         /* a real parading as a VF_COMPLEX */
-        v->v_compdata = TREALLOC(ngcomplex_t, v->v_compdata, v->v_length + 1);
         v->v_compdata[v->v_length].cx_real = value;
         v->v_compdata[v->v_length].cx_imag = 0.0;
     }
@@ -1082,7 +1100,9 @@ plotAddComplexValue(dataDesc *desc, IFcomplex value)
 {
     struct dvec *v = desc->vec;
 
-    v->v_compdata = TREALLOC(ngcomplex_t, v->v_compdata, v->v_length + 1);
+    if (v->v_length >= v->v_alloc_length)
+        dvec_extend(v, v->v_length + vlength2delta(v->v_length));
+
     v->v_compdata[v->v_length].cx_real = value.real;
     v->v_compdata[v->v_length].cx_imag = value.imag;
 
diff --git a/src/include/ngspice/dvec.h b/src/include/ngspice/dvec.h
index eb5a9a9ae..77eb6f179 100644
--- a/src/include/ngspice/dvec.h
+++ b/src/include/ngspice/dvec.h
@@ -45,6 +45,7 @@ struct dvec {
     GRIDTYPE v_gridtype;	/* One of GRID_*. */
     PLOTTYPE v_plottype;	/* One of PLOT_*. */
     int v_length;		/* Length of the vector. */
+    int v_alloc_length;		/* How much has been actually allocated. */
     int v_rlength;		/* How much space we really have. Used as binary flag */
     int v_outindex;		/* Index if writedata is building the
 				   vector. */
@@ -70,6 +71,7 @@ struct dveclist {
 
 struct dvec *dvec_alloc(char *name, int type, short flags, int length, void *storage);
 void dvec_realloc(struct dvec *v, int length, void *storage);
+void dvec_extend(struct dvec *v, int length);
 void dvec_trunc(struct dvec *v, int length);
 void dvec_free(struct dvec *);