added basic string builder

string_builder.c

@@ -0,0 +1,114 @@
+#include "cig.h"
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+
+string_builder_t sb_create(allocator_t builder_allocator) {
+	return (string_builder_t) {
+		.allocator=builder_allocator,
+		.head=NULL,
+		.tail=NULL
+	};
+}
+
+void sb_add_string(string_builder_t *this, const char *string) {
+	string_builder_node_t *node = allocator_alloc(this->allocator, sizeof(string_builder_node_t));
+	node->length = strlen(string);
+	node->string = string;
+	node->next = NULL;
+	if (this->tail == NULL) {
+		assert(this->head == NULL);
+		this->head = node;
+		this->tail = node;
+	} else {
+		this->tail->next = node;
+		this->tail = node;
+	}
+}
+
+void sb_add_i64(string_builder_t *this, int64_t i64) {
+	// 21 bytes is the max needed ever for a 64 bit integer, even unsigned.
+	const unsigned long max_size = 21;
+	char *buffer = allocator_alloc(this->allocator, max_size);
+	snprintf(buffer, max_size, "%"PRIi64, i64);
+	sb_add_string(this, buffer);
+}
+
+void sb_add_i32(string_builder_t *this, int32_t i32) {
+	const unsigned long max_size = 21;
+	char *buffer = allocator_alloc(this->allocator, max_size);
+	snprintf(buffer, max_size, "%"PRIi32, i32);
+	sb_add_string(this, buffer);
+}
+
+void sb_add_i16(string_builder_t *this, int16_t i16) {
+	const unsigned long max_size = 21;
+	char *buffer = allocator_alloc(this->allocator, max_size);
+	snprintf(buffer, max_size, "%"PRIi16, i16);
+	sb_add_string(this, buffer);
+}
+
+void sb_add_i8(string_builder_t *this, int8_t i8) {
+	const unsigned long max_size = 21;
+	char *buffer = allocator_alloc(this->allocator, max_size);
+	snprintf(buffer, max_size, "%"PRIi8, i8);
+	sb_add_string(this, buffer);
+}
+
+void sb_add_u64(string_builder_t *this, uint64_t u64) {
+	const unsigned long max_size = 21;
+	char *buffer = allocator_alloc(this->allocator, max_size);
+	snprintf(buffer, max_size, "%"PRIu64, u64);
+	sb_add_string(this, buffer);
+}
+
+void sb_add_u32(string_builder_t *this, uint32_t u32) {
+	const unsigned long max_size = 21;
+	char *buffer = allocator_alloc(this->allocator, max_size);
+	snprintf(buffer, max_size, "%"PRIu32, u32);
+	sb_add_string(this, buffer);
+}
+
+void sb_add_u16(string_builder_t *this, uint16_t u16) {
+	const unsigned long max_size = 21;
+	char *buffer = allocator_alloc(this->allocator, max_size);
+	snprintf(buffer, max_size, "%"PRIu16, u16);
+	sb_add_string(this, buffer);
+}
+
+void sb_add_u8(string_builder_t *this, uint8_t u8) {
+	const unsigned long max_size = 21;
+	char *buffer = allocator_alloc(this->allocator, max_size);
+	snprintf(buffer, max_size, "%"PRIu8, u8);
+	sb_add_string(this, buffer);
+}
+
+const char *sb_build(
+	string_builder_t *this,
+	allocator_t output_allocator
+) {
+	size_t total_length = 0;
+	for (
+		string_builder_node_t *node = this->head;
+		node != NULL;
+		node = node->next
+	) {
+		total_length += node->length;
+	}
+	total_length++; // null character
+	char *buffer = allocator_alloc(output_allocator, total_length * sizeof(char));
+	size_t i = 0;
+	for (
+		string_builder_node_t *node = this->head;
+		node != NULL;
+		node = node->next
+	) {
+		for (const char *c = node->string; (*c) != '\0'; c++) {
+			buffer[i] = *c;
+			i++;
+		}
+	}
+	buffer[total_length-1] = '\0';
+	return buffer;
+}