text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <assert.h>
  #include <string.h>
  
  #include "py/runtime.h"
  #include "py/builtin.h"
  #include "py/stream.h"
  #include "py/objstringio.h"
  #include "py/frozenmod.h"
  
  #if MICROPY_PY_IO
  
  extern const mp_obj_type_t mp_type_fileio;
  extern const mp_obj_type_t mp_type_textio;
  
  #if MICROPY_PY_IO_BUFFEREDWRITER
  typedef struct _mp_obj_bufwriter_t {
      mp_obj_base_t base;
      mp_obj_t stream;
      size_t alloc;
      size_t len;
      byte buf[0];
  } mp_obj_bufwriter_t;
  
  STATIC mp_obj_t bufwriter_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      mp_arg_check_num(n_args, n_kw, 2, 2, false);
      size_t alloc = mp_obj_get_int(args[1]);
      mp_obj_bufwriter_t *o = m_new_obj_var(mp_obj_bufwriter_t, byte, alloc);
      o->base.type = type;
      o->stream = args[0];
      o->alloc = alloc;
      o->len = 0;
      return o;
  }
  
  STATIC mp_uint_t bufwriter_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *errcode) {
      mp_obj_bufwriter_t *self = MP_OBJ_TO_PTR(self_in);
  
      mp_uint_t org_size = size;
  
      while (size > 0) {
          mp_uint_t rem = self->alloc - self->len;
          if (size < rem) {
              memcpy(self->buf + self->len, buf, size);
              self->len += size;
              return org_size;
          }
  
          // Buffer flushing policy here is to flush entire buffer all the time.
          // This allows e.g. to have a block device as backing storage and write
          // entire block to it. memcpy below is not ideal and could be optimized
          // in some cases. But the way it is now it at least ensures that buffer
          // is word-aligned, to guard against obscure cases when it matters, e.g.
          // https://github.com/micropython/micropython/issues/1863
          memcpy(self->buf + self->len, buf, rem);
          buf = (byte*)buf + rem;
          size -= rem;
          mp_uint_t out_sz = mp_stream_write_exactly(self->stream, self->buf, self->alloc, errcode);
          if (*errcode != 0) {
              return MP_STREAM_ERROR;
          }
          // TODO: try to recover from a case of non-blocking stream, e.g. move
          // remaining chunk to the beginning of buffer.
          assert(out_sz == self->alloc);
          self->len = 0;
      }
  
      return org_size;
  }
  
  STATIC mp_obj_t bufwriter_flush(mp_obj_t self_in) {
      mp_obj_bufwriter_t *self = MP_OBJ_TO_PTR(self_in);
  
      if (self->len != 0) {
          int err;
          mp_uint_t out_sz = mp_stream_write_exactly(self->stream, self->buf, self->len, &err);
          // TODO: try to recover from a case of non-blocking stream, e.g. move
          // remaining chunk to the beginning of buffer.
          assert(out_sz == self->len);
          self->len = 0;
          if (err != 0) {
              mp_raise_OSError(err);
          }
      }
  
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_1(bufwriter_flush_obj, bufwriter_flush);
  
  STATIC const mp_rom_map_elem_t bufwriter_locals_dict_table[] = {
      { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
      { MP_ROM_QSTR(MP_QSTR_flush), MP_ROM_PTR(&bufwriter_flush_obj) },
  };
  STATIC MP_DEFINE_CONST_DICT(bufwriter_locals_dict, bufwriter_locals_dict_table);
  
  STATIC const mp_stream_p_t bufwriter_stream_p = {
      .write = bufwriter_write,
  };
  
  STATIC const mp_obj_type_t bufwriter_type = {
      { &mp_type_type },
      .name = MP_QSTR_BufferedWriter,
      .make_new = bufwriter_make_new,
      .protocol = &bufwriter_stream_p,
      .locals_dict = (mp_obj_dict_t*)&bufwriter_locals_dict,
  };
  #endif // MICROPY_PY_IO_BUFFEREDWRITER
  
  #if MICROPY_MODULE_FROZEN_STR
  STATIC mp_obj_t resource_stream(mp_obj_t package_in, mp_obj_t path_in) {
      VSTR_FIXED(path_buf, MICROPY_ALLOC_PATH_MAX);
      size_t len;
  
      // As an extension to pkg_resources.resource_stream(), we support
      // package parameter being None, the path_in is interpreted as a
      // raw path.
      if (package_in != mp_const_none) {
          mp_obj_t args[5];
          args[0] = package_in;
          args[1] = mp_const_none; // TODO should be globals
          args[2] = mp_const_none; // TODO should be locals
          args[3] = mp_const_true; // Pass sentinel "non empty" value to force returning of leaf module
          args[4] = MP_OBJ_NEW_SMALL_INT(0);
  
          // TODO lookup __import__ and call that instead of going straight to builtin implementation
          mp_obj_t pkg = mp_builtin___import__(5, args);
  
          mp_obj_t dest[2];
          mp_load_method_maybe(pkg, MP_QSTR___path__, dest);
          if (dest[0] == MP_OBJ_NULL) {
              mp_raise_TypeError(NULL);
          }
  
          const char *path = mp_obj_str_get_data(dest[0], &len);
          vstr_add_strn(&path_buf, path, len);
          vstr_add_byte(&path_buf, '/');
      }
  
      const char *path = mp_obj_str_get_data(path_in, &len);
      vstr_add_strn(&path_buf, path, len);
  
      len = path_buf.len;
      const char *data = mp_find_frozen_str(path_buf.buf, &len);
      if (data != NULL) {
          mp_obj_stringio_t *o = m_new_obj(mp_obj_stringio_t);
          o->base.type = &mp_type_bytesio;
          o->vstr = m_new_obj(vstr_t);
          vstr_init_fixed_buf(o->vstr, len + 1, (char*)data);
          o->vstr->len = len;
          o->pos = 0;
          return MP_OBJ_FROM_PTR(o);
      }
  
      mp_obj_t path_out = mp_obj_new_str(path_buf.buf, path_buf.len, false);
      return mp_builtin_open(1, &path_out, (mp_map_t*)&mp_const_empty_map);
  }
  MP_DEFINE_CONST_FUN_OBJ_2(resource_stream_obj, resource_stream);
  #endif
  
  STATIC const mp_rom_map_elem_t mp_module_io_globals_table[] = {
      { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_uio) },
      // Note: mp_builtin_open_obj should be defined by port, it's not
      // part of the core.
      { MP_ROM_QSTR(MP_QSTR_open), MP_ROM_PTR(&mp_builtin_open_obj) },
      #if MICROPY_PY_IO_RESOURCE_STREAM
      { MP_ROM_QSTR(MP_QSTR_resource_stream), MP_ROM_PTR(&resource_stream_obj) },
      #endif
      #if MICROPY_PY_IO_FILEIO
      { MP_ROM_QSTR(MP_QSTR_FileIO), MP_ROM_PTR(&mp_type_fileio) },
      #if MICROPY_CPYTHON_COMPAT
      { MP_ROM_QSTR(MP_QSTR_TextIOWrapper), MP_ROM_PTR(&mp_type_textio) },
      #endif
      #endif
      { MP_ROM_QSTR(MP_QSTR_StringIO), MP_ROM_PTR(&mp_type_stringio) },
      #if MICROPY_PY_IO_BYTESIO
      { MP_ROM_QSTR(MP_QSTR_BytesIO), MP_ROM_PTR(&mp_type_bytesio) },
      #endif
      #if MICROPY_PY_IO_BUFFEREDWRITER
      { MP_ROM_QSTR(MP_QSTR_BufferedWriter), MP_ROM_PTR(&bufwriter_type) },
      #endif
  };
  
  STATIC MP_DEFINE_CONST_DICT(mp_module_io_globals, mp_module_io_globals_table);
  
  const mp_obj_module_t mp_module_io = {
      .base = { &mp_type_module },
      .globals = (mp_obj_dict_t*)&mp_module_io_globals,
  };
  
  #endif
  