From fba5295502b1f6b3913ef6a7b5cdda3deb118f41 Mon Sep 17 00:00:00 2001
From: M4x1m3 <M4x1me@protonmail.com>
Date: Sun, 5 Jul 2020 15:24:31 +0200
Subject: [PATCH] [mpy/files] readline

---
 python/port/genhdr/qstrdefs.in.h |   1 +
 python/port/mod/ion/file.cpp     | 110 +++++++++++++++++++++++--------
 2 files changed, 82 insertions(+), 29 deletions(-)

diff --git a/python/port/genhdr/qstrdefs.in.h b/python/port/genhdr/qstrdefs.in.h
index 7d3a3f8be..52bd80e5a 100644
--- a/python/port/genhdr/qstrdefs.in.h
+++ b/python/port/genhdr/qstrdefs.in.h
@@ -504,6 +504,7 @@ Q(fileno)
 Q(flush)
 Q(isatty)
 Q(readable)
+Q(readline)
 Q(seekable)
 Q(write)
 Q(writable)
diff --git a/python/port/mod/ion/file.cpp b/python/port/mod/ion/file.cpp
index bbccad466..0fbd9941a 100644
--- a/python/port/mod/ion/file.cpp
+++ b/python/port/mod/ion/file.cpp
@@ -32,6 +32,14 @@ const mp_obj_fun_builtin_var_t file_seek_obj = {
     {(mp_fun_var_t)file_seek}
 };
 
+STATIC mp_obj_t file_readline(size_t n_args, const mp_obj_t* args);
+
+const mp_obj_fun_builtin_var_t file_readline_obj = {
+    {&mp_type_fun_builtin_var},
+    MP_OBJ_FUN_MAKE_SIG(1, 2, false),
+    {(mp_fun_var_t)file_readline}
+};
+
 STATIC mp_obj_t file_read(size_t n_args, const mp_obj_t* args);
 
 const mp_obj_fun_builtin_var_t file_read_obj = {
@@ -212,6 +220,9 @@ STATIC void file_attr(mp_obj_t self_in, qstr attribute, mp_obj_t *destination) {
             case MP_QSTR_read:
                 destination[0] = (mp_obj_t) MP_ROM_PTR(&file_read_obj);
                 break;
+            case MP_QSTR_readline:
+                destination[0] = (mp_obj_t) MP_ROM_PTR(&file_readline_obj);
+                break;
             case MP_QSTR_write:
                 destination[0] = (mp_obj_t) MP_ROM_PTR(&file_write_obj);
                 break;
@@ -663,6 +674,46 @@ STATIC mp_obj_t file_write(mp_obj_t o_in, mp_obj_t o_s) {
     return mp_obj_new_int(len);
 }
 
+STATIC mp_obj_t __file_read_backend(file_obj_t* file, mp_int_t size, bool with_line_sep) {
+    if (file->location == RAM) {
+        size_t file_size = file->record.value().size;
+        size_t start = file->position;
+        if (start >= file_size || size == 0) {
+            if (file->binary_mode == TEXT)
+                return mp_obj_new_str("", 0);
+            if (file->binary_mode == BINARY)
+                return mp_const_empty_bytes;
+        }
+        
+        size_t end = 0;
+        
+        // size == 0 handled earlier.
+        if (size < 0) {
+            end = file_size;
+        } else {
+            end = std::min(file_size, file->position + size);
+        }
+        
+        if (with_line_sep) {
+            for(size_t i = start; i < end; i++) {
+                if (*((uint8_t*)(file->record.value().buffer) + i) == '\n') {
+                    end = i + 1;
+                    break;
+                }
+            }
+        }
+        
+        file->position = end;
+        
+        if (file->binary_mode == TEXT)
+            return mp_obj_new_str((const char*)file->record.value().buffer + start, end - start);
+        if (file->binary_mode == BINARY)
+            return mp_obj_new_bytes((const byte*)file->record.value().buffer + start, end - start);
+    }
+    
+    return mp_const_none;
+}
+
 STATIC mp_obj_t file_read(size_t n_args, const mp_obj_t* args) {
     mp_arg_check_num(n_args, 0, 1, 2, false);
     
@@ -687,34 +738,35 @@ STATIC mp_obj_t file_read(size_t n_args, const mp_obj_t* args) {
         
         size = mp_obj_get_int(args[1]);
     }
-    
-    if (file->location == RAM) {
-        size_t file_size = file->record.value().size;
-        size_t start = file->position;
-        if (start >= file_size || size == 0) {
-            if (file->binary_mode == TEXT)
-                return mp_obj_new_str("", 0);
-            if (file->binary_mode == BINARY)
-                return mp_const_empty_bytes;
-        }
-        
-        size_t end = 0;
-        
-        // size == 0 handled earlier.
-        if (size < 0) {
-            end = file_size;
-        } else {
-            end = std::min(file_size, file->position + size);
-        }
-        
-        file->position = end;
-        
-        if (file->binary_mode == TEXT)
-            return mp_obj_new_str((const char*)file->record.value().buffer + start, end - start);
-        if (file->binary_mode == BINARY)
-            return mp_obj_new_bytes((const byte*)file->record.value().buffer + start, end - start);
-    }
-    
-    return mp_const_none;
+
+    return __file_read_backend(file, size, false);
+}
+
+STATIC mp_obj_t file_readline(size_t n_args, const mp_obj_t* args) {
+    mp_arg_check_num(n_args, 0, 1, 2, false);
+    
+    if(!mp_obj_is_type(args[0], &file_type)) {
+        mp_raise_TypeError("self must be a file!");
+    }
+
+    file_obj_t *file = (file_obj_t*) MP_OBJ_TO_PTR(args[0]);
+    
+    check_closed(file);
+    
+    if (file->open_mode != READ && file->edit_mode != true) {
+        mp_raise_OSError(1);
+    }
+    
+    mp_int_t size = -1;
+    
+    if (n_args > 1) {
+        if (!mp_obj_is_integer(args[1])) {
+            mp_raise_ValueError("size must be an int!");
+        }
+        
+        size = mp_obj_get_int(args[1]);
+    }
+
+    return __file_read_backend(file, size, true);
 }