Fix loading the search paths for DCP files and add XDG_CONFIG_HOME as extra path

src/dcp.c

@@ -3,35 +3,121 @@
 #include <libdng.h>
 #include <libmegapixels.h>
 #include <malloc.h>
+#include <stdarg.h>
 #include <stdbool.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #ifndef SYSCONFDIR
 #include "config.h"
 #endif
 
-bool
+char *
-find_calibration(size_t size, char *conffile, const char *sensor)
+mprintf(const char *fmt, ...)
 {
-        char model[512];
+        char *str = NULL;
-        int model_found = libmegapixels_get_model(sizeof(model), model);
+        va_list args;
-        if(!model_found)
+        va_start(args, fmt);
-                return false;
+        va_list args_copy;
-        static const char *paths[] = {
+        va_copy(args_copy, args);
-                "config/%s,%s.dcp",
+        int len = vsnprintf(NULL, 0, fmt, args);
-                SYSCONFDIR "/megapixels/config/%s,%s.dcp",
+        va_end(args);
-                DATADIR "/megapixels/config/%s,%s.dcp",
+        if (len < 0) {
-                NULL
+                goto out;
-        };
+        }
-        for (const char **fmt = paths; *fmt; fmt++) {
+        str = malloc(len + 1);
-                snprintf(conffile, size, *fmt, model, sensor);
+        if (str == NULL) {
+                goto out;
+        }
+        vsnprintf(str, len + 1, fmt, args_copy);
+out:
+        va_end(args_copy);
+        return str;
+}
+
+char *
+mread(const char *path, long *size_out)
+{
+        FILE *src = fopen(path, "r");
+        if (src == NULL) {
+                return NULL;
+        }
+        fseek(src, 0L, SEEK_END);
+        long src_size = ftell(src);
+        rewind(src);
+        char *data = malloc(src_size + 1);
+        if (data == NULL) {
+                return data;
+        }
+        fread(data, src_size, 1, src);
+        fclose(src);
+        data[src_size] = '\0';
+        if (size_out != NULL) {
+                *size_out = src_size;
+        }
+        return data;
+}
+
+bool
+find_calibration_by_model(size_t maxlen,
+                          char *conffile,
+                          char *model,
+                          const char *sensor)
+{
+        const char *home = getenv("HOME");
+        char *config_home = getenv("XDG_CONFIG_HOME");
+        int fch = 0;
+        if ((config_home == NULL || config_home[0] == '\0') && home != NULL) {
+                config_home = mprintf("%s/.config", home);
+                fch = 1;
+        }
+        // Check in XDG_CONFIG_HOME/megapixels/config
+        snprintf(conffile,
+                 maxlen,
+                 "%s/megapixels/config/%s.conf",
+                 config_home,
+                 model);
+        if (access(conffile, F_OK) != -1) {
+                if (fch) {
+                        free(config_home);
+                }
+                return true;
+        }
+
+        static const char *paths[] = { "config/%s,%s.dcp",
+                                       SYSCONFDIR "/megapixels/config/%s,%s.dcp",
+                                       DATADIR "/megapixels/config/%s,%s.dcp",
+                                       NULL };
+        for (const char *fmt = paths[0]; fmt; fmt++) {
+                snprintf(conffile, maxlen, fmt, model, sensor);
                 if (access(conffile, F_OK) != -1) {
                         printf("Found calibration file at %s\n", conffile);
                         return true;
                 }
         }
-        printf("No calibration found for %s,%s\n", model, sensor);
+        return false;
+}
+
+bool
+find_calibration(size_t maxlen, char *conffile, const char *sensor)
+{
+        long size = 0;
+        char *compatible = mread("/proc/device-tree/compatible", &size);
+        if (compatible == NULL) {
+                return false;
+        }
+
+        char *modelptr = compatible;
+        while ((modelptr - compatible) < size) {
+                if (find_calibration_by_model(maxlen, conffile, modelptr, sensor)) {
+                        free(compatible);
+                        return true;
+                }
+                modelptr += strlen(modelptr) + 1;
+        }
+        free(compatible);
+        printf("No calibration found %s\n", sensor);
         return false;
 }