gfio: Add mini library to draw bar graphs and line graphs

Signed-off-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/graph.c b/graph.c
new file mode 100644
index 0000000..3e76fa9
--- /dev/null
+++ b/graph.c
@@ -0,0 +1,626 @@
+/*
+ * gfio - gui front end for fio - the flexible io tester
+ *
+ * Copyright (C) 2012 Stephen M. Cameron <stephenmcameron@gmail.com> 
+ *
+ * The license below covers all files distributed with fio unless otherwise
+ * noted in the file itself.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  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
+ *
+ */
+#include <string.h>
+#include <malloc.h>
+#include <math.h>
+#include <assert.h>
+
+#include <cairo.h>
+#include <gtk/gtk.h>
+
+#include "tickmarks.h"
+
+struct xyvalue {
+	double x, y;
+};
+
+struct graph_value {
+	struct graph_value *next;
+	void *value;
+};
+
+struct graph_label {
+	char *label;
+	struct graph_value *tail;
+	struct graph_value *values;
+	struct graph_label *next;
+	double r, g, b;
+	int value_count;
+	struct graph *parent;
+};
+
+struct graph {
+	char *title;
+	char *xtitle;
+	char *ytitle;
+	int xdim, ydim;
+	struct graph_label *labels;
+	struct graph_label *tail;
+	int per_label_limit;
+};
+
+struct graph *graph_new(int xdim, int ydim)
+{
+	struct graph *g;
+
+	g = calloc(1, sizeof(*g));
+	g->xdim = xdim;
+	g->ydim = ydim;
+	g->per_label_limit = -1;
+	return g;
+}
+
+static int count_labels(struct graph_label *labels)
+{
+	int count = 0;
+	struct graph_label *i;
+
+	for (i = labels; i; i = i->next)
+		count++;
+	return count;
+}
+
+static int count_values(struct graph_value *values)
+{
+	int count = 0;
+	struct graph_value *i;
+
+	for (i = values; i; i = i->next)
+		count++;
+	return count;
+}
+
+typedef double (*double_comparator)(double a, double b);
+
+static double mindouble(double a, double b)
+{
+	return a < b ? a : b;
+}
+
+static double maxdouble(double a, double b)
+{
+	return a < b ? b : a;
+}
+
+static double find_double_values(struct graph_value *values, double_comparator cmp)
+{
+	struct graph_value *i;
+	int first = 1;
+	double answer, tmp;
+
+	assert(values != NULL);
+	answer = 0.0; /* shut the compiler up, might need to think harder though. */
+	for (i = values; i; i = i->next) {
+		tmp = *(double *) i->value; 
+		if (first) {
+			answer = tmp;
+			first = 0;
+		} else {
+			answer = cmp(answer, tmp);
+		}
+	}
+	return answer;
+}
+
+static double find_double_data(struct graph_label *labels, double_comparator cmp)
+{
+	struct graph_label *i;
+	int first = 1;
+	double answer, tmp;
+
+	assert(labels != NULL);
+	answer = 0.0; /* shut the compiler up, might need to think harder though. */
+	for (i = labels; i; i = i->next) {
+		tmp = find_double_values(i->values, cmp);
+		if (first) {
+			answer = tmp;
+			first = 0;
+		} else {
+			answer = cmp(tmp, answer);
+		}
+	}
+	return answer;
+}
+
+static double find_min_data(struct graph_label *labels)
+{
+	return find_double_data(labels, mindouble);
+}
+
+static double find_max_data(struct graph_label *labels)
+{
+	return find_double_data(labels, maxdouble);
+}
+
+static void draw_bars(struct graph *bg, cairo_t *cr, struct graph_label *lb,
+			double label_offset, double bar_width,
+			double mindata, double maxdata)
+{
+	struct graph_value *i;
+	double x1, y1, x2, y2;
+	int bar_num = 0;
+	double domain, range, v;
+
+	domain = (maxdata - mindata);
+	range = (double) bg->ydim * 0.80; /* FIXME */
+	cairo_stroke(cr);
+	for (i = lb->values; i; i = i->next) {
+
+		x1 = label_offset + (double) bar_num * bar_width + (bar_width * 0.05);
+		x2 = x1 + bar_width * 0.90;
+		y2 = bg->ydim * 0.90;
+		v = *(double *) i->value;
+		y1 = y2 - (((v - mindata) / domain) * range);
+		cairo_move_to(cr, x1, y1);
+		cairo_line_to(cr, x1, y2);
+		cairo_line_to(cr, x2, y2);
+		cairo_line_to(cr, x2, y1);
+		cairo_close_path(cr);
+		cairo_fill(cr);
+		cairo_stroke(cr);
+		bar_num++;	
+	}
+}
+
+static void draw_centered_text(cairo_t *cr, double x, double y,
+		double fontsize, const char *text)
+{
+	cairo_text_extents_t extents;
+
+	cairo_select_font_face (cr, "Sans",
+		CAIRO_FONT_SLANT_NORMAL,
+		CAIRO_FONT_WEIGHT_NORMAL);
+
+	cairo_set_font_size(cr, fontsize);
+	cairo_text_extents(cr, text, &extents);
+	x = x - (extents.width / 2 + extents.x_bearing);
+	y = y - (extents.height / 2 + extents.y_bearing);
+
+	cairo_move_to(cr, x, y);
+	cairo_show_text(cr, text);
+}
+
+static void draw_vertical_centered_text(cairo_t *cr, double x, double y,
+		double fontsize, const char *text)
+{
+	double sx, sy;
+	cairo_text_extents_t extents;
+
+	cairo_select_font_face (cr, "Sans",
+		CAIRO_FONT_SLANT_NORMAL,
+		CAIRO_FONT_WEIGHT_NORMAL);
+
+	cairo_set_font_size(cr, fontsize);
+	cairo_text_extents(cr, text, &extents);
+	sx = x;
+	sy = y;
+	y = y + (extents.width / 2.0 + extents.x_bearing);
+	x = x - (extents.height / 2.0 + extents.y_bearing);
+
+	cairo_move_to(cr, x, y);
+	cairo_save(cr);
+	cairo_translate(cr, -sx, -sy);
+	cairo_rotate(cr, -90.0 * M_PI / 180.0);
+	cairo_translate(cr, sx, sy);
+	cairo_show_text(cr, text);
+	cairo_restore(cr);
+}
+
+static void graph_draw_common(struct graph *g, cairo_t *cr,
+	double *x1, double *y1, double *x2, double *y2)
+{
+        cairo_set_source_rgb(cr, 0, 0, 0);
+        cairo_set_line_width (cr, 1.0);
+
+        cairo_move_to(cr, 0, 0);
+        cairo_line_to(cr, 0, g->ydim);
+        cairo_line_to(cr, g->xdim, g->ydim);
+        cairo_line_to(cr, g->xdim, 0);
+        cairo_line_to(cr, 0, 0);
+
+	/* for now just set margins at 10% of width.  This is not very good. */
+	*x1 = g->xdim / 10.0;	
+	*x2 = 9.0 * *x1; 
+	*y1 = g->ydim / 10.0;	
+	*y2 = 9.0 * *y1; 
+
+	cairo_move_to(cr, *x1, *y1);
+	cairo_line_to(cr, *x1, *y2);
+	cairo_line_to(cr, *x2, *y2);
+	cairo_line_to(cr, *x2, *y1);
+	cairo_line_to(cr, *x1, *y1);
+	cairo_stroke(cr);
+
+	draw_centered_text(cr, g->xdim / 2, g->ydim / 20, 20.0, g->title);
+	draw_centered_text(cr, g->xdim / 2, g->ydim * 0.97, 14.0, g->xtitle);
+	draw_vertical_centered_text(cr, g->xdim * 0.02, g->ydim / 2, 14.0, g->ytitle);
+	cairo_stroke(cr);
+}
+
+static void graph_draw_x_ticks(struct graph *g, cairo_t *cr,
+	double x1, double y1, double x2, double y2,
+	double minx, double maxx, int nticks)
+{
+	struct tickmark *tm;
+	double tx;
+	int i;
+	static double dash[] = { 1.0, 2.0 };
+
+	nticks = calc_tickmarks(minx, maxx, nticks, &tm);
+
+	for (i = 0; i < nticks; i++) {
+		tx = (((tm[i].value) - minx) / (maxx - minx)) * (x2 - x1) + x1;
+		if (tx < x1 || tx > x2)
+			continue;
+
+		/* Draw tick mark */
+		cairo_set_line_width(cr, 1.0);
+		cairo_move_to(cr, tx, y2);
+		cairo_line_to(cr, tx, y2 + (y2 - y1) * 0.03);
+		cairo_stroke(cr);
+
+		/* draw grid lines */
+		cairo_save(cr);
+		cairo_set_dash(cr, dash, 2, 2.0);
+		cairo_set_line_width(cr, 0.5);
+		cairo_move_to(cr, tx, y1);
+		cairo_line_to(cr, tx, y2);
+		cairo_stroke(cr);
+		cairo_restore(cr);
+
+		/* draw tickmark label */
+		draw_centered_text(cr, tx, y2 * 1.04, 12.0, tm[i].string);
+		cairo_stroke(cr);
+		
+	}
+}
+
+static void graph_draw_y_ticks(struct graph *g, cairo_t *cr,
+	double x1, double y1, double x2, double y2,
+	double miny, double maxy, int nticks)
+{
+	struct tickmark *tm;
+	double ty;
+	int i;
+	static double dash[] = { 2.0, 2.0 };
+
+	nticks = calc_tickmarks(miny, maxy, nticks, &tm);
+
+	for (i = 0; i < nticks; i++) {
+		ty = y2 - (((tm[i].value) - miny) / (maxy - miny)) * (y2 - y1);
+		if (ty < y1 || ty > y2)
+			continue;
+		/* draw tick mark */
+		cairo_move_to(cr, x1, ty);
+		cairo_line_to(cr, x1 - (x2 - x1) * 0.02, ty);
+		cairo_stroke(cr);
+
+		/* draw grid lines */
+		cairo_save(cr);
+		cairo_set_dash(cr, dash, 2, 2.0);
+		cairo_set_line_width(cr, 0.5);
+		cairo_move_to(cr, x1, ty);
+		cairo_line_to(cr, x2, ty);
+		cairo_stroke(cr);
+		cairo_restore(cr);
+
+		/* draw tickmark label */
+		draw_centered_text(cr, x1 - (x2 - x1) * 0.04, ty, 12.0, tm[i].string);
+		cairo_stroke(cr);
+	}
+}
+
+void bar_graph_draw(struct graph *bg, cairo_t *cr)
+{
+	double x1, y1, x2, y2;
+	double space_per_label, bar_width;
+	double label_offset, mindata, maxdata;
+	int i, nlabels;
+	struct graph_label *lb;
+
+	cairo_save(cr);
+	graph_draw_common(bg, cr, &x1, &y1, &x2, &y2);
+
+	nlabels = count_labels(bg->labels);
+	space_per_label = (x2 - x1) / (double) nlabels; 
+
+	mindata = find_min_data(bg->labels);
+	maxdata = find_max_data(bg->labels);
+
+	if (fabs(maxdata - mindata) < 1e-20) {
+		draw_centered_text(cr,
+			x1 + (x2 - x1) / 2.0,
+			y1 + (y2 - y1) / 2.0, 20.0, "No good data");
+		return;
+	}
+
+	graph_draw_y_ticks(bg, cr, x1, y1, x2, y2, mindata, maxdata, 10);
+
+	i = 0;
+	for (lb = bg->labels; lb; lb = lb->next) {
+		int nvalues;
+		nvalues = count_values(lb->values);
+		bar_width = (space_per_label - space_per_label * 0.2) / (double) nvalues;
+		label_offset = bg->xdim * 0.1 + space_per_label * (double) i + space_per_label * 0.1;
+		draw_bars(bg, cr, lb, label_offset, bar_width, mindata, maxdata);
+		// draw_centered_text(cr, label_offset + (bar_width / 2.0 + bar_width * 0.1), bg->ydim * 0.93,
+		draw_centered_text(cr, x1 + space_per_label * (i + 0.5), bg->ydim * 0.93,
+			12.0, lb->label); 
+		i++;
+	}
+	cairo_stroke(cr);
+	cairo_restore(cr);
+}
+
+typedef double (*xy_value_extractor)(struct graph_value *v);
+
+static double getx(struct graph_value *v)
+{
+	struct xyvalue *xy = v->value;
+	return xy->x;
+}
+
+static double gety(struct graph_value *v)
+{
+	struct xyvalue *xy = v->value;
+	return xy->y;
+}
+
+static double find_xy_value(struct graph *g, xy_value_extractor getvalue, double_comparator cmp)
+{
+	double tmp, answer = 0.0;
+	struct graph_label *i;
+	struct graph_value *j;
+
+	for (i = g->labels; i; i = i->next)
+		for (j = i->values; j; j = j->next) {
+			tmp = getvalue(j);
+			answer = cmp(tmp, answer);	
+		}
+	return answer;
+} 
+
+void line_graph_draw(struct graph *g, cairo_t *cr)
+{
+	double x1, y1, x2, y2;
+	double minx, miny, maxx, maxy;
+	double tx, ty;
+	struct graph_label *i;
+	struct graph_value *j;
+	int first = 1;
+
+	cairo_save(cr);
+	graph_draw_common(g, cr, &x1, &y1, &x2, &y2);
+
+	minx = find_xy_value(g, getx, mindouble);
+	maxx = find_xy_value(g, getx, maxdouble);
+	miny = find_xy_value(g, gety, mindouble);
+	maxy = find_xy_value(g, gety, maxdouble);
+
+	if (fabs(maxx - minx) < 1e-20 || fabs(maxy - miny) < 1e-20) {
+		draw_centered_text(cr,
+			x1 + (x2 - x1) / 2.0,
+			y1 + (y2 - y1) / 2.0, 20.0, "No good Data");
+		return;
+	}
+
+	graph_draw_x_ticks(g, cr, x1, y1, x2, y2, minx, maxx, 10);
+	graph_draw_y_ticks(g, cr, x1, y1, x2, y2, miny, maxy, 10);
+
+	cairo_set_line_width(cr, 2.5);
+	for (i = g->labels; i; i = i->next) {
+		first = 1;
+		cairo_set_source_rgb(cr, i->r, i->g, i->b);
+		for (j = i->values; j; j = j->next) {
+			tx = ((getx(j) - minx) / (maxx - minx)) * (x2 - x1) + x1;
+			ty = y2 - ((gety(j) - miny) / (maxy - miny)) * (y2 - y1);
+			if (first) {
+				cairo_move_to(cr, tx, ty);
+				first = 0;
+			} else {
+				cairo_line_to(cr, tx, ty);
+			}
+		}
+		cairo_stroke(cr);
+	}
+	cairo_restore(cr);
+}
+
+static void gfree(void *f)
+{
+	if (f)
+		free(f);
+}
+
+static void setstring(char **str, const char *value)
+{
+	gfree(*str);
+	*str = strdup(value);
+}
+
+void graph_title(struct graph *bg, const char *title)
+{
+	setstring(&bg->title, title);
+}
+
+void graph_x_title(struct graph *bg, const char *title)
+{
+	setstring(&bg->xtitle, title);
+}
+
+void graph_y_title(struct graph *bg, const char *title)
+{
+	setstring(&bg->ytitle, title);
+}
+
+static struct graph_label *graph_find_label(struct graph *bg,
+				const char *label)
+{
+	struct graph_label *i;
+	
+	for (i = bg->labels; i; i = i->next)
+		if (strcmp(label, i->label) == 0)
+			return i;
+	return NULL;
+}
+
+void graph_add_label(struct graph *bg, const char *label)
+{
+	struct graph_label *i;
+	
+	i = graph_find_label(bg, label);
+	if (i)
+		return; /* already present. */
+	i = calloc(1, sizeof(*i));
+	i->parent = bg;
+	setstring(&i->label, label);
+	i->next = NULL;
+	if (!bg->tail)
+		bg->labels = i;
+	else
+		bg->tail->next = i;
+	bg->tail = i;
+}
+
+static void graph_label_add_value(struct graph_label *i, void *value)
+{
+	struct graph_value *x;
+
+	x = malloc(sizeof(*x));
+	x->value = value;
+	x->next = NULL;
+	if (!i->tail) {
+		i->values = x;
+	} else {
+		i->tail->next = x;
+	}
+	i->tail = x;
+	i->value_count++;
+
+	if (i->parent->per_label_limit != -1 &&
+		i->value_count > i->parent->per_label_limit) {
+		x = i->values;
+		i->values = i->values->next;
+		free(x->value);
+		free(x);
+		i->value_count--;
+	}
+}
+
+int graph_add_data(struct graph *bg, const char *label, const double value)
+{
+	struct graph_label *i;
+	double *d;
+
+	d = malloc(sizeof(*d));
+	*d = value;
+
+	i = graph_find_label(bg, label);
+	if (!i)
+		return -1;
+	graph_label_add_value(i, d);
+	return 0;
+}
+
+int graph_add_xy_data(struct graph *bg, const char *label,
+		const double x, const double y)
+{
+	struct graph_label *i;
+	struct xyvalue *xy;
+
+	xy = malloc(sizeof(*xy));
+	xy->x = x;
+	xy->y = y;
+
+	i = graph_find_label(bg, label);
+	if (!i)
+		return -1;
+	graph_label_add_value(i, xy);
+	return 0;
+}
+
+static void graph_free_values(struct graph_value *values)
+{
+	struct graph_value *i, *next;
+
+	for (i = values; i; i = next) {
+		next = i->next;
+		gfree(i->value);
+		gfree(i);
+	}	
+}
+
+static void graph_free_labels(struct graph_label *labels)
+{
+	struct graph_label *i, *next;
+
+	for (i = labels; i; i = next) {
+		next = i->next;
+		graph_free_values(i->values);
+		gfree(i);
+	}	
+}
+
+void graph_set_color(struct graph *gr, const char *label,
+	double red, double green, double blue)
+{
+	struct graph_label *i;
+	double r, g, b;
+
+	r = fabs(red);
+	g = fabs(green);
+	b = fabs(blue);
+
+	if (r > 1.0)
+		r = 1.0;
+	if (g > 1.0)
+		g = 1.0;
+	if (b > 1.0)
+		b =1.0;
+
+	for (i = gr->labels; i; i = i->next)
+		if (strcmp(i->label, label) == 0) {
+			i->r = r;	
+			i->g = g;	
+			i->b = b;	
+			break;
+		}
+}
+
+void graph_free(struct graph *bg)
+{
+	gfree(bg->title);
+	gfree(bg->xtitle);
+	gfree(bg->ytitle);
+	graph_free_labels(bg->labels);
+}
+
+/* For each line in the line graph, up to per_label_limit segments may
+ * be added.  After that, adding more data to the end of the line
+ * causes data to drop off of the front of the line.
+ */
+void line_graph_set_data_count_limit(struct graph *g, int per_label_limit)
+{
+	g->per_label_limit = per_label_limit;
+}
+