port SQLite fork to wasm

sdk/allocator.c

@@ -0,0 +1,13 @@
+#include "allocator.h"
+#include <stdlib.h>
+
+#define UNUSED(x) (void)(x)
+
+void *allocate(size_t size) {
+    return malloc(size);
+}
+
+void deallocate(void *ptr, size_t size) {
+    UNUSED(size);
+    free(ptr);
+}

sdk/allocator.h

@@ -0,0 +1,27 @@
+#ifndef C_SDK_ALLOCATOR_H
+#define C_SDK_ALLOCATOR_H
+
+#include <stddef.h> // for size_t
+
+/**
+ * Allocates a memory region of given size.
+ *
+ * Used by Wasm VM for byte array passing. Should be exported from module.
+ *
+ * @param size a size of needed memory region.
+ * @return a pointer to allocated memory region.
+ */
+void *allocate(size_t size);
+
+/**
+ * Frees a memory region.
+ *
+ * Used by Wasm VM for freeing previous memory allocated by `allocate` function.
+ * Should be exported from module.
+ *
+ * @param ptr the pointer to the previously allocated memory region.
+ * @param size the size of the previously allocated memory region.
+ */
+void deallocate(void *ptr, size_t size);
+
+#endif //C_SDK_ALLOCATOR_H

sdk/logger.c

@@ -0,0 +1,15 @@
+#include "logger.h"
+
+#define __LOGGER_IMPORT(name) \
+    __attribute__((__import_module__("logger"), __import_name__(#name)))
+
+void __write(char ch) __LOGGER_IMPORT(write);
+void __flush() __LOGGER_IMPORT(flush);
+
+void wasm_log(const char *str, int len) {
+    for(int byteId = 0; byteId < len; ++byteId) {
+        __write(str[byteId]);
+    }
+
+    __flush();
+}

sdk/logger.h

@@ -0,0 +1,11 @@
+#ifndef C_SDK_LOGGER_H
+#define C_SDK_LOGGER_H
+
+/**
+ * Writes provided string to Wasm VM logger.
+ *
+ * @param log_message a message that should be logged.
+ */
+void wasm_log(const char *str, int len);
+
+#endif //C_SDK_LOGGER_H