<html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> <div class="moz-cite-prefix">On 01/13/2014 08:27 PM, Paul Berry wrote: </div> <blockquote cite="mid:CA+yLL643VMP11DQsDQDPsR3H5DWY6C7wcUg_pEJc6P-VBCLENQ@mail.gmail.com" type="cite"> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <div dir="ltr">On 2 January 2014 03:58, Tapani Pälli <<a moz-do-not-send="true" href="mailto:tapani.palli@intel.com" target="_blank">tapani.palli@intel.com</a>> wrote: <div class="gmail_extra"> <div class="gmail_quote"> <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Class will be used by the shader binary cache implementation. Signed-off-by: Tapani Pälli <<a moz-do-not-send="true" href="mailto:tapani.palli@intel.com">tapani.palli@intel.com</a>> --- src/glsl/memory_writer.h | 147 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 src/glsl/memory_writer.h diff --git a/src/glsl/memory_writer.h b/src/glsl/memory_writer.h new file mode 100644 index 0000000..a6c6b55 --- /dev/null +++ b/src/glsl/memory_writer.h @@ -0,0 +1,147 @@ +/* -*- c++ -*- */ +/* + * Copyright © 2013 Intel Corporation + * + * 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 (including the next + * paragraph) 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. + */ + +#pragma once +#ifndef MEMORY_WRITER_H +#define MEMORY_WRITER_H + +#include <stdlib.h> +#include <unistd.h> +#include <string.h> + +#ifdef __cplusplus +/** + * Helper class for writing data to memory + * + * This class maintains a dynamically-sized memory buffer and allows + * for data to be efficiently appended to it with automatic resizing. + */ +class memory_writer +{ +public: + memory_writer() : + memory(NULL), + curr_size(0), + pos(0) {} + + ~memory_writer() + { + free(memory); + } + + /* user wants to claim the memory */ + char *release_memory(size_t *size) + { + /* final realloc to free allocated but unused memory */ + char *result = (char *) realloc(memory, pos); + *size = pos; + memory = NULL; + curr_size = 0; + pos = 0; + return result; + } + +/** + * write functions per type + */ +#define DECL_WRITER(type) int write_ ##type (const type data) {\ + return write(&data, sizeof(type));\ +} + + DECL_WRITER(int32_t); + DECL_WRITER(int64_t); + DECL_WRITER(uint8_t); + DECL_WRITER(uint32_t); + + int write_bool(bool data) + { + uint8_t val = data; + return write_uint8_t(val); + } + + /* write function that reallocates more memory if required */ + int write(const void *data, int32_t size) + { + if (!memory || pos > (int32_t)(curr_size - size)) + if (grow(size)) + return -1; + + memcpy(memory + pos, data, size); + + pos += size; + return 0; + } + + int overwrite(const void *data, int32_t size, int32_t offset) + { + if (offset < 0 || offset + size > pos) + return -1; + memcpy(memory + offset, data, size); + return 0; + } + + int write_string(const char *str) + { + if (!str) + return -1; + char terminator = '\0'; + write(str, strlen(str)); + write(&terminator, 1); </blockquote> <div> </div> <div>C strings include a terminator, so there's no reason to write out the string contents and the terminator separtely. You can just do: </div> <div>write(str, strlen(str) + 1); Also, don't forget to propagate the return code to the caller: </div> <div>return write(str, strlen(str) + 1); </div> </div> </div> </div> </blockquote> Ah right, will do. It could be that this needs to be modified back to how it was though (to write to length of the string too). I think it is otherwise impossible for the reader side to know if terminator really exists and it might continue to read forever (or call strlen for unterminated string). <blockquote cite="mid:CA+yLL643VMP11DQsDQDPsR3H5DWY6C7wcUg_pEJc6P-VBCLENQ@mail.gmail.com" type="cite"> <div dir="ltr"> <div class="gmail_extra"> <div class="gmail_quote"> <div> </div> <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> + return 0; + } + + inline int32_t position() { return pos; } + + +private: + + /* reallocate more memory */ + int grow(int32_t size) + { + int32_t new_size = 2 * (curr_size + size); + char *more_mem = (char *) realloc(memory, new_size); + if (more_mem == NULL) { + free(memory); + memory = NULL; + return -1; + } else { + memory = more_mem; + curr_size = new_size; + return 0; + } + } + + /* allocated memory */ + char *memory; + + /* current size of the whole allocation */ + int32_t curr_size; + + /* write position / size of the data written */ + int32_t pos; +}; + +#endif /* ifdef __cplusplus */ + +#endif /* MEMORY_WRITER_H */ -- 1.8.3.1 </blockquote> </div> </div> </div> </blockquote> </body> </html>