From 21aefd281a88849b30067c7d2471ff09b317e8fd Mon Sep 17 00:00:00 2001
From: jacekpoz <jacekpoz@cock.li>
Date: Fri, 9 Feb 2024 15:10:13 +0100
Subject: [PATCH] general memory and readability improvements

---
 modfetch.c | 79 +++++++++++++++++++++++++++++++++---------------------
 1 file changed, 49 insertions(+), 30 deletions(-)

diff --git a/modfetch.c b/modfetch.c
index 121dcad..fdcccaa 100644
--- a/modfetch.c
+++ b/modfetch.c
@@ -16,7 +16,10 @@ static const uint8_t VERSION_PATCH = 0;
 
 static const uint8_t MAX_MODULE_NAME_LENGTH = 128;
 static const uint8_t MAX_MODULES = 128;
-static const uint8_t MAX_MODULE_VARS = 128;
+
+static const uint8_t INITIAL_CONFIG_SIZE = 8;
+
+static const uint16_t MAX_PATH_LENGTH = 4096;
 
 static const char *version_str(void) {
     char *ver;
@@ -44,7 +47,7 @@ void parsing_error(size_t line) {
 }
 
 char *remove_whitespaces(const char *str) {
-    char *tmp = malloc(strlen(str) * sizeof(char));
+    char tmp[strlen(str)];
     size_t i = 0;
     size_t j = 0;
     while (str[i] != '\0') {
@@ -60,17 +63,17 @@ char *remove_whitespaces(const char *str) {
 
     char *ret = malloc(j * sizeof(char));
     strncpy(ret, tmp, j);
-    free(tmp);
 
     return ret;
 }
 
 char *resolve_env_vars(const char *str) {
     size_t len = strlen(str);
-    char *ret = malloc(4096 * sizeof(char));
+    char *ret = malloc(MAX_PATH_LENGTH * sizeof(char));
     size_t ret_offset = 0;
     bool in_env_var = false;
-    char *env_var = malloc(4096 * sizeof(char));
+    char env_var[MAX_PATH_LENGTH];
+    memset(env_var, 0, sizeof(env_var));
     size_t env_var_offset = 0;
 
     for (size_t i = 0; i < len; ++i) {
@@ -86,14 +89,14 @@ char *resolve_env_vars(const char *str) {
             continue;
         }
 
+        // end of current env var
         if (in_env_var && !(isalpha(str[i]) || isdigit(str[i]) || str[i] == '_')) {
             in_env_var = false;
 
             char *env = getenv(env_var);
             strcat(ret, env);
             ret_offset += strlen(env);
-            free(env_var);
-            env_var = malloc(4096 * sizeof(char));
+            memset(env_var, 0, sizeof(env_var));
             env_var_offset = 0;
         }
 
@@ -107,8 +110,13 @@ char *resolve_env_vars(const char *str) {
         ++ret_offset;
     }
 
-    free(env_var);
+    return ret;
+}
 
+char *process_str(const char *str) {
+    char *whitespaceless = remove_whitespaces(str);
+    char *ret = resolve_env_vars(whitespaceless);
+    free(whitespaceless);
     return ret;
 }
 
@@ -119,33 +127,36 @@ Config parse_config(FILE *config_file) {
     size_t line_index = 0;
     bool in_config = false; 
 
-    char *current_path = malloc(MAX_MODULE_NAME_LENGTH * sizeof(char));
+    char current_path[MAX_MODULE_NAME_LENGTH];
     Module current_module = {
-        .path = malloc(4096 * sizeof(char)),
-        .config = malloc(MAX_MODULE_VARS * sizeof(char)),
+        .path = NULL,
+        .config = NULL,
     };
     size_t config_index = 0;
+    size_t config_multiplier = 1;
     
     Config config = {
         .modules = malloc(MAX_MODULES * sizeof(Module)),
         .module_count = 0,
     };
-    size_t module_index = 0;
 
+    // TODO rewrite this to read the config char by char
     while ((read = getline(&line, &len, config_file)) != -1) {
-        if (read == 1)
+        if (read <= 1)
             continue;
-        // if config is passed
+
+        // if config is passed to this module
         if (line[read - 2u] == '{') {
             if (in_config) {
                 fclose(config_file);
                 parsing_error(line_index);
             }
             in_config = true;
+            // get rid of the '{'
             strncpy(current_path, line, (size_t)read - 2);
-            current_module.path = resolve_env_vars(remove_whitespaces(current_path));
-            free(current_path);
-            current_path = malloc(MAX_MODULE_NAME_LENGTH);
+
+            current_module.path = process_str(current_path);
+            current_module.config = malloc(INITIAL_CONFIG_SIZE * sizeof(char*));
             continue;
         }
 
@@ -156,31 +167,39 @@ Config parse_config(FILE *config_file) {
                 parsing_error(line_index);
             }
             in_config = false;
+
+            if (config_index >= INITIAL_CONFIG_SIZE * config_multiplier) {
+                config_multiplier *= 2;
+                current_module.config = realloc(current_module.config, INITIAL_CONFIG_SIZE * config_multiplier);
+            }
             current_module.config[config_index] = NULL;
-            config.modules[module_index] = current_module;
-            ++module_index;
-            current_module.path = malloc(4096 * sizeof(char));
-            current_module.config = malloc(MAX_MODULE_VARS * sizeof(char));
+            config.modules[config.module_count] = current_module;
+            ++config.module_count;
+            config_index = 0;
             continue;
         }
 
         if (in_config) {
-            current_module.config[config_index] = remove_whitespaces(line);
+            if (config_index >= INITIAL_CONFIG_SIZE * config_multiplier) {
+                config_multiplier *= 2;
+                current_module.config = realloc(current_module.config, INITIAL_CONFIG_SIZE * config_multiplier);
+            }
+            current_module.config[config_index] = process_str(line);
             ++config_index;
             continue;
         }
 
-        current_module.path = resolve_env_vars(remove_whitespaces(line));
-        free(current_module.config);
+        // no config passed to this module
+        current_module.path = process_str(line);
+
         current_module.config = malloc(sizeof(void*));
         current_module.config[0] = NULL;
-        config.modules[module_index] = current_module;
-        ++module_index;
-        current_module.path = malloc(4096 * sizeof(char));
-        current_module.config = malloc(MAX_MODULE_VARS * sizeof(char));
-    }
 
-    config.module_count = module_index;
+        config.modules[config.module_count] = current_module;
+        ++config.module_count;
+
+        free(line);
+    }
 
     return config;
 }