libpotoml: allow getting parameters from subsets

common/hashtable.c

@@ -9,7 +9,7 @@
 // After these operations, a simple character folding algorithm is
 // applied, based on multiplying by a prime number, choosen here for
 // operations on chars.
-unsigned char common_hashtable_compute_hash(char *str, unsigned char modulus) {
+unsigned char common_hashtable_compute_hash(const char *str, unsigned char modulus) {
 	unsigned char result = 0;
 	unsigned char extended_char;
 
@@ -62,7 +62,7 @@ void common_hashtable_free(struct CommonHashtableTable *hashtable) {
 // Elements are stored in a plane of the hashtable size, and collisions are
 // solved by finding the first empty place after the theoretical (hash-given)
 // element's position.
-struct CommonHashtableElement *common_hashtable_find(struct CommonHashtableTable *hashtable, char *name) {
+struct CommonHashtableElement *common_hashtable_find(struct CommonHashtableTable *hashtable, const char *name) {
 	struct CommonHashtableElement *el;
 	unsigned char initial_pos;
 	unsigned char pos;
@@ -80,7 +80,7 @@ struct CommonHashtableElement *common_hashtable_find(struct CommonHashtableTable
 	return NULL;
 }
 
-bool common_hashtable_insert(struct CommonHashtableTable *hashtable, char *name, void *content) {
+bool common_hashtable_insert(struct CommonHashtableTable *hashtable, const char *name, void *content) {
 	struct CommonHashtableElement *el;
 	unsigned char initial_pos;
 	unsigned char pos;

include/common/hashtable.h

@@ -17,9 +17,9 @@ struct CommonHashtableElement {
 	void *content;
 };
 
-unsigned char common_hashtable_compute_hash(char *str, unsigned char modulus);
+unsigned char common_hashtable_compute_hash(const char *str, unsigned char modulus);
 bool common_hashtable_initialize(struct CommonHashtableTable *hashtable, unsigned char hashtable_size);
 void common_hashtable_free(struct CommonHashtableTable *hashtable);
-struct CommonHashtableElement *common_hashtable_find(struct CommonHashtableTable *hashtable, char *name);
-bool common_hashtable_insert(struct CommonHashtableTable *hashtable, char *name, void *content);
+struct CommonHashtableElement *common_hashtable_find(struct CommonHashtableTable *hashtable, const char *name);
+bool common_hashtable_insert(struct CommonHashtableTable *hashtable, const char *name, void *content);
 

include/libpotoml/toml.h

@@ -26,7 +26,17 @@ enum PotomlState {
 	PotomlPropertyValueDouble = 0x41,
 };
 
+struct PotomlTomlSubset {
+	struct CommonHashtableTable *hashtable;
+	char *section_name;
+	size_t section_name_length;
+};
+
 char potoml_toml_parse(struct CommonHashtableTable *hashtable, char *toml);
 char potoml_toml_parse_file(struct CommonHashtableTable *hashtable, char *toml_file_path);
+struct PotomlTomlSubset *potoml_toml_create_subset(struct CommonHashtableTable *hashtable, const char *section_name);
+char *potoml_toml_get_string(struct PotomlTomlSubset *subset, const char *property);
+double potoml_toml_get_double(struct PotomlTomlSubset *subset, const char *property);
+void potoml_toml_subset_free(struct PotomlTomlSubset *subset);
 void potoml_toml_free(struct CommonHashtableTable *hashtable);
 

libpotoml/toml.c

@@ -160,6 +160,79 @@ char potoml_toml_parse_file(struct CommonHashtableTable *hashtable, char *toml_f
 	return out;
 }
 
+struct PotomlTomlSubset *potoml_toml_create_subset(struct CommonHashtableTable *hashtable, const char *section_name) {
+	struct PotomlTomlSubset *subset;
+
+	size_t section_name_length = strlen(section_name);
+	char *owned_section_name = malloc((section_name_length + 2) * sizeof(char));
+
+	if(!owned_section_name) return NULL;
+
+	// Append dot to section name
+	strcpy(owned_section_name, section_name);
+	strcat(owned_section_name, ".");
+
+	subset = (struct PotomlTomlSubset *) malloc(sizeof(struct PotomlTomlSubset));
+
+	if(!subset) return NULL;
+
+	subset->hashtable = hashtable;
+	subset->section_name = owned_section_name;
+	subset->section_name_length = section_name_length + 1;
+
+	return subset;
+}
+
+char *potoml_toml_get_string(struct PotomlTomlSubset *subset, const char *property) {
+	struct CommonHashtableElement *el;
+
+	size_t property_length;
+	char *full_property;
+
+	property_length = strlen(property);
+
+	full_property = (char *) malloc((property_length + subset->section_name_length + 1) * sizeof(char));
+	strcpy(full_property, subset->section_name);
+	strcat(full_property, property);
+
+	el = common_hashtable_find(subset->hashtable, full_property);
+	if(!el) {
+		return NULL;
+	}
+
+	free(full_property);
+	return (char *) el->content;
+}
+
+double potoml_toml_get_double(struct PotomlTomlSubset *subset, const char *property) {
+	struct CommonHashtableElement *el;
+
+	size_t property_length;
+	double value;
+	char *full_property;
+
+	value = 0.0;
+	property_length = strlen(property);
+
+	full_property = (char *) malloc(property_length + subset->section_name_length + 1);
+	strcpy(full_property, subset->section_name);
+	strcat(full_property, property);
+
+	el = common_hashtable_find(subset->hashtable, full_property);
+	if(el) {
+		// Clone instead of giving reference for double
+		value = *((double *) el->content);
+	}
+
+	free(full_property);
+	return value;
+}
+
+void potoml_toml_subset_free(struct PotomlTomlSubset *subset) {
+	free((void *) subset->section_name);
+	free((void *) subset);
+}
+
 void potoml_toml_free(struct CommonHashtableTable *hashtable) {
 	unsigned char i;
 	struct CommonHashtableElement *el;