2 files changed, 85 insertions, 4 deletions

diff --git a/src/system/fileutils.c b/src/system/fileutils.c
index dc8eaca..86d176a 100644
--- a/src/system/fileutils.c
+++ b/src/system/fileutils.c
@@ -1,5 +1,6 @@
 #include "../../include/mgl/system/fileutils.h"
 #include <sys/stat.h>
+#include <sys/mman.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <stdlib.h>
@@ -49,3 +50,71 @@ void mgl_filedata_free(mgl_filedata *self) {
     self->data = NULL;
     self->size = 0;
 }
+
+static int load_options_to_open_flag(mgl_memory_mapped_file_load_options *load_options) {
+    const bool readable = load_options ? load_options->readable : true;
+    const bool writable = load_options ? load_options->writable : true;
+
+    int open_flag = 0;
+    if(readable && writable)
+        open_flag = O_RDWR;
+    else if(readable)
+        open_flag = O_RDONLY;
+    else if(writable)
+        open_flag = O_WRONLY;
+
+    return open_flag;
+}
+
+static int load_options_to_mmap_prot_flag(mgl_memory_mapped_file_load_options *load_options) {
+    const bool readable = load_options ? load_options->readable : true;
+    const bool writable = load_options ? load_options->writable : true;
+
+    int prot_flag = 0;
+    if(readable)
+        prot_flag |= PROT_READ;
+    if(writable)
+        prot_flag |= PROT_WRITE;
+
+    return prot_flag;
+}
+
+int mgl_mapped_file_load(const char *filepath, mgl_memory_mapped_file *memory_mapped_file, mgl_memory_mapped_file_load_options *load_options) {
+    memory_mapped_file->data = NULL;
+    memory_mapped_file->size = 0;
+    memory_mapped_file->fd = -1;
+
+    int fd = open(filepath, load_options_to_open_flag(load_options));
+    if(fd == -1)
+        return -1;
+
+    struct stat st;
+    if(fstat(fd, &st) == -1) {
+        close(fd);
+        return -1;
+    }
+
+    void *mapped = mmap(0, st.st_size, load_options_to_mmap_prot_flag(load_options), MAP_SHARED, fd, 0);
+    if(mapped == MAP_FAILED) {
+        close(fd);
+        return -1;
+    }
+
+    memory_mapped_file->data = mapped;
+    memory_mapped_file->size = st.st_size;
+    memory_mapped_file->fd = fd;
+    return 0;
+}
+
+void mgl_mapped_file_unload(mgl_memory_mapped_file *memory_mapped_file) {
+    if(memory_mapped_file->data != MAP_FAILED && memory_mapped_file->data != NULL) {
+        munmap(memory_mapped_file->data, memory_mapped_file->size);
+        memory_mapped_file->data = NULL;
+    }
+    memory_mapped_file->size = 0;
+
+    if(memory_mapped_file->fd != -1) {
+        close(memory_mapped_file->fd);
+        memory_mapped_file->fd = -1;
+    }
+}
diff --git a/src/system/utf8.c b/src/system/utf8.c
index 35b0f2f..201fedf 100644
--- a/src/system/utf8.c
+++ b/src/system/utf8.c
@@ -20,19 +20,31 @@ static inline bool utf8_get_codepoint_length(unsigned char b, size_t *codepoint_
 
 /* TODO: Optimize (remove branching, etc) */
 bool mgl_utf8_decode(const unsigned char *str, size_t size, uint32_t *decoded_codepoint, size_t *codepoint_length) {
-    if(size == 0)
+    if(size == 0) {
+        *decoded_codepoint = 0;
+        *codepoint_length = 0;
         return false;
+    }
 
     size_t clen;
-    if(!utf8_get_codepoint_length(str[0], &clen))
+    if(!utf8_get_codepoint_length(str[0], &clen)) {
+        *decoded_codepoint = str[0];
+        *codepoint_length = 1;
         return false;
+    }
 
-    if(size < clen)
+    if(size < clen) {
+        *decoded_codepoint = str[0];
+        *codepoint_length = 1;
         return false;
+    }
 
     for(size_t i = 1; i < clen; ++i) {
-        if((str[i] & 0xC0) != 0x80)
+        if((str[i] & 0xC0) != 0x80) {
+            *decoded_codepoint = str[0];
+            *codepoint_length = 1;
             return false;
+        }
     }
 
     uint32_t codepoint;