Move plotting functions to gnuplot.[c,h]

* Set Options and parse_options to static
* Check -f argument receives a valid string
* Change data_total from int to size_t
* Print option.filename instead of argv[1] before reading the mstat file
* Fix allocation size of gp array
* Add better ticmarks
* Increase line width to 1.
* Bugfix: wait for user to close gnuplot window before exiting
* Bugfix: free pointers to axis_y and gp

1 files changed, 16 insertions, 152 deletions

diff --git a/mstat_plot.c b/mstat_plot.c
index 3ccf888..fd32582 100644
--- a/mstat_plot.c
+++ b/mstat_plot.c
@@ -1,147 +1,14 @@
-//
-// Created by jhunk on 8/24/22.
-//
-
-#include <string.h>
-#include <stdarg.h>
 #include "common.h"
+#include "gnuplot.h"
 
 extern char *mstat_field_names[];
 
-struct GNUPLOT_PLOT {
-   char *title;
-   char *xlabel;
-   char *ylabel;
-   char *line_type;
-   double line_width;
-   unsigned int line_color;
-   unsigned char grid_toggle;
-   unsigned char autoscale_toggle;
-   unsigned char legend_toggle;
-   unsigned char legend_enhanced;
-   char *legend_title;
-};
-
-struct Option {
+static struct Option {
     unsigned char verbose;
     char *fields[0xffff];
     char filename[PATH_MAX];
 } option;
 
-
-/**
- * Open a new gnuplot handle
- * @return stream on success, or NULL on error
- */
-FILE *gnuplot_open() {
-    // -p = persistent window after exit
-    return popen("gnuplot -p", "w");
-}
-
-/**
- * Close a gnuplot handle
- * @param fp pointer to gnuplot stream
- * @return 0 on success, or <0 on error
- */
-int gnuplot_close(FILE *fp) {
-    return pclose(fp);
-}
-
-/**
- * Send shell command to gnuplot instance
- * @param fp pointer to gnuplot stream
- * @param fmt command to execute (requires caller to end string with a LF "\n")
- * @param ... formatter arguments
- * @return value of `vfprintf()`. <0 on error
- */
-int gnuplot_sh(FILE *fp, char *fmt, ...) {
-    int status;
-
-    va_list args;
-    va_start(args, fmt);
-    status = vfprintf(fp, fmt, args);
-    va_end(args);
-
-    return status;
-}
-
-/**
- * Generate a plot
- * Each GNUPLOT_PLOT pointer in the `gp` array corresponds to a line.
- * @param fp pointer to gnuplot stream
- * @param gp pointer to an array of GNUPLOT_PLOT structures
- * @param x an array representing the x axis
- * @param y an array of double-precision arrays representing the y axes
- * @param x_count total length of array x
- * @param y_count total number of arrays in y
- */
-void gnuplot_plot(FILE *fp, struct GNUPLOT_PLOT **gp, double x[], double *y[], size_t x_count, size_t y_count) {
-    // Configure plot
-    gnuplot_sh(fp, "set title '%s'\n", gp[0]->title);
-    gnuplot_sh(fp, "set xlabel '%s'\n", gp[0]->xlabel);
-    gnuplot_sh(fp, "set ylabel '%s'\n", gp[0]->ylabel);
-    if (gp[0]->grid_toggle)
-        gnuplot_sh(fp, "set grid\n");
-    if (gp[0]->autoscale_toggle)
-        gnuplot_sh(fp, "set autoscale\n");
-    if (gp[0]->legend_toggle) {
-        gnuplot_sh(fp, "set key nobox\n");
-        //gnuplot_sh(fp, "set key bmargin\n");
-        gnuplot_sh(fp, "set key font ',5'\n");
-        gnuplot_sh(fp, "set key outside\n");
-    }
-    if (gp[0]->legend_enhanced) {
-        gnuplot_sh(fp, "set key enhanced\n");
-    } else {
-        gnuplot_sh(fp, "set key noenhanced\n");
-    }
-
-    // Begin plotting
-    gnuplot_sh(fp, "plot ");
-    for (size_t i = 0; i < y_count; i++) {
-        char pltbuf[1024] = {0};
-        sprintf(pltbuf, "'-' ");
-        if (gp[0]->legend_toggle) {
-            sprintf(pltbuf + strlen(pltbuf), "title '%s' ", gp[i]->legend_title);
-            sprintf(pltbuf + strlen(pltbuf), "with lines ");
-            if (gp[i]->line_width) {
-                sprintf(pltbuf + strlen(pltbuf), "lw %0.1f ", gp[i]->line_width);
-            }
-            if (gp[i]->line_type) {
-                sprintf(pltbuf + strlen(pltbuf), "lt %s ", gp[i]->line_type);
-            }
-            if (gp[i]->line_color) {
-                sprintf(pltbuf + strlen(pltbuf), "lc rgb '#%06x' ", gp[i]->line_color);
-            }
-            gnuplot_sh(fp, "%s ", pltbuf);
-        } else {
-            gnuplot_sh(fp, "with lines ");
-        }
-        if (i < y_count - 1) {
-            gnuplot_sh(fp, ", ");
-        }
-    }
-    gnuplot_sh(fp, "\n");
-
-    // Emit MSTAT data
-    for (size_t arr = 0; arr < y_count; arr++) {
-        for (size_t i = 0; i < x_count; i++) {
-            gnuplot_sh(fp, "%lf %lf\n", x[i], y[arr][i]);
-        }
-        // Commit plot and execute
-        gnuplot_sh(fp, "e\n");
-    }
-    fflush(fp);
-}
-
-unsigned int rgb(unsigned char r, unsigned char g, unsigned char b) {
-    unsigned int result = r;
-    result = result << 8 | g;
-    result = result << 8 | b;
-    return result;
-}
-
-
 static void show_fields(char **fields) {
     size_t total;
     for (total = 0; fields[total] != NULL; total++);
@@ -174,7 +41,7 @@ static void usage(char *prog) {
            "", name);
 }
 
-void parse_options(int argc, char *argv[]) {
+static void parse_options(int argc, char *argv[]) {
     if (argc < 2) {
         usage(argv[0]);
         exit(1);
@@ -187,7 +54,7 @@ void parse_options(int argc, char *argv[]) {
 
     for (int x = 0, i = 1; i < argc; i++) {
         char *arg = argv[i];
-        if (strlen(argv[i]) > 1 && !strncmp(argv[i], "-", 1)) {
+        if (strlen(arg) > 1 && !strncmp(arg, "-", 1)) {
             arg = argv[i] + 1;
             if (!strcmp(arg, "h")) {
                 usage(argv[0]);
@@ -201,6 +68,7 @@ void parse_options(int argc, char *argv[]) {
                 option.verbose = 1;
             }
             if (!strcmp(arg, "f")) {
+                mstat_check_argument_str(argv, arg, i);
                 char *val = argv[i+1];
                 char *token = NULL;
                 if (!val) {
@@ -230,7 +98,7 @@ int main(int argc, char *argv[]) {
     struct mstat_record_t p;
     char **stored_fields;
     char **field;
-    int data_total;
+    size_t data_total;
     double **axis_y;
     double *axis_x;
     double mem_min, mem_max;
@@ -242,7 +110,6 @@ int main(int argc, char *argv[]) {
     parse_options(argc, argv);
 
     rec = 0;
-    data_total = 0;
     mem_min = 0.0;
     mem_max = 0.0;
     field = option.fields;
@@ -298,13 +165,13 @@ int main(int argc, char *argv[]) {
     }
 
     mstat_rewind(fp);
-    printf("Reading: %s\n", argv[1]);
+    printf("Reading: %s\n", option.filename);
 
     // Assign requested MSTAT data to y-axis. x-axis will always be time elapsed.
     rec = 0;
     while (!mstat_iter(fp, &p)) {
         axis_x[rec] = mstat_get_field_by_name(&p, "timestamp").d64 / 3600;
-        for (int i = 0; i < data_total; i++) {
+        for (size_t i = 0; i < data_total; i++) {
             axis_y[i][rec] = (double) mstat_get_field_by_name(&p, field[i]).u64 / 1024;
         }
         rec++;
@@ -328,7 +195,7 @@ int main(int argc, char *argv[]) {
         exit(1);
     }
 
-    struct GNUPLOT_PLOT **gp = calloc(data_total, sizeof(**gp));
+    struct GNUPLOT_PLOT **gp = calloc(data_total + 1, sizeof(*gp[0]));
     if (!gp) {
         perror("Unable to allocate memory for gnuplot configuration array");
         exit(1);
@@ -342,27 +209,22 @@ int main(int argc, char *argv[]) {
         }
     }
 
-    unsigned char r, g, b;
     char title[255] = {0};
-    r = 0x10;
-    g = 0x20;
-    b = 0x30;
     snprintf(title, sizeof(title) - 1, "Memory Usage (PID %d)", p.pid);
 
     gp[0]->xlabel = strdup("Time (HR)");
     gp[0]->ylabel = strdup("MB");
     gp[0]->title = strdup(title);
     gp[0]->grid_toggle = 1;
+    gp[0]->grid_mytics = 5;
+    gp[0]->grid_mxtics = 5;
     gp[0]->autoscale_toggle = 1;
     gp[0]->legend_toggle = 1;
 
     for (size_t i = 0; i < data_total; i++) {
         gp[i]->legend_title = strdup(field[i]);
-        gp[i]->line_color = rgb(r, g, b);
-        gp[i]->line_width = 0.50;
-        r -= 0x30;
-        b += 0x20;
-        g *= 3;
+        gp[i]->line_width = 1.0;
+        gp[i]->line_color = 0;
     }
 
     printf("Generating plot... ");
@@ -375,6 +237,7 @@ int main(int argc, char *argv[]) {
         exit(1);
     }
     gnuplot_plot(plt, gp, axis_x, axis_y, rec, data_total);
+    gnuplot_wait(plt);
     gnuplot_close(plt);
     printf("done!\n");
 
@@ -383,6 +246,7 @@ int main(int argc, char *argv[]) {
         free(axis_y[i]);
         free(gp[i]);
     }
-
+    free(axis_y);
+    free(gp);
     return 0;
 }