1 //===-- String writer for printf --------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_LIBC_SRC_STDIO_PRINTF_CORE_WRITER_H
10 #define LLVM_LIBC_SRC_STDIO_PRINTF_CORE_WRITER_H
11 
12 #include <stddef.h>
13 
14 namespace __llvm_libc {
15 namespace printf_core {
16 
17 using WriteFunc = void (*)(void *, const char *__restrict, size_t);
18 
19 class Writer final {
20   // output is a pointer to the string or file that the writer is meant to write
21   // to.
22   void *output;
23 
24   // raw_write is a function that, when called on output with a char* and
25   // length, will copy the number of bytes equal to the length from the char*
26   // onto the end of output.
27   WriteFunc raw_write;
28 
29   size_t max_length;
30   size_t chars_written;
31 
32 public:
33   Writer(void *output, WriteFunc raw_write, size_t max_length);
34 
35   // write will copy length bytes from new_string into output using
36   // raw_write, unless that would cause more bytes than max_length to be
37   // written. It always increments chars_written by length.
38   void write(const char *new_string, size_t length);
39 
40   // write_chars will copy length copies of new_char into output using raw_write
41   // unless that would cause more bytes than max_length to be written. It always
42   // increments chars_written by length.
43   void write_chars(char new_char, size_t length);
44 
45   size_t get_chars_written();
46 };
47 
48 } // namespace printf_core
49 } // namespace __llvm_libc
50 
51 #endif // LLVM_LIBC_SRC_STDIO_PRINTF_CORE_WRITER_H
52