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Diffstat (limited to 'vendor/github.com/ethereum/ethash/src/libethash/io.h')
| -rw-r--r-- | vendor/github.com/ethereum/ethash/src/libethash/io.h | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/vendor/github.com/ethereum/ethash/src/libethash/io.h b/vendor/github.com/ethereum/ethash/src/libethash/io.h new file mode 100644 index 000000000..7a27089c7 --- /dev/null +++ b/vendor/github.com/ethereum/ethash/src/libethash/io.h @@ -0,0 +1,202 @@ +/* + This file is part of ethash. + + ethash is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + ethash is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with ethash. If not, see <http://www.gnu.org/licenses/>. +*/ +/** @file io.h + * @author Lefteris Karapetsas <lefteris@ethdev.com> + * @date 2015 + */ +#pragma once +#include <stdlib.h> +#include <stdint.h> +#include <stdbool.h> +#include <stdio.h> +#ifdef __cplusplus +#define __STDC_FORMAT_MACROS 1 +#endif +#include <inttypes.h> +#include "endian.h" +#include "ethash.h" + +#ifdef __cplusplus +extern "C" { +#endif +// Maximum size for mutable part of DAG file name +// 6 is for "full-R", the suffix of the filename +// 10 is for maximum number of digits of a uint32_t (for REVISION) +// 1 is for - and 16 is for the first 16 hex digits for first 8 bytes of +// the seedhash and last 1 is for the null terminating character +// Reference: https://github.com/ethereum/wiki/wiki/Ethash-DAG +#define DAG_MUTABLE_NAME_MAX_SIZE (6 + 10 + 1 + 16 + 1) +/// Possible return values of @see ethash_io_prepare +enum ethash_io_rc { + ETHASH_IO_FAIL = 0, ///< There has been an IO failure + ETHASH_IO_MEMO_SIZE_MISMATCH, ///< DAG with revision/hash match, but file size was wrong. + ETHASH_IO_MEMO_MISMATCH, ///< The DAG file did not exist or there was revision/hash mismatch + ETHASH_IO_MEMO_MATCH, ///< DAG file existed and revision/hash matched. No need to do anything +}; + +// small hack for windows. I don't feel I should use va_args and forward just +// to have this one function properly cross-platform abstracted +#if defined(_WIN32) && !defined(__GNUC__) +#define snprintf(...) sprintf_s(__VA_ARGS__) +#endif + +/** + * Logs a critical error in important parts of ethash. Should mostly help + * figure out what kind of problem (I/O, memory e.t.c.) causes a NULL + * ethash_full_t + */ +#ifdef ETHASH_PRINT_CRITICAL_OUTPUT +#define ETHASH_CRITICAL(...) \ + do \ + { \ + printf("ETHASH CRITICAL ERROR: "__VA_ARGS__); \ + printf("\n"); \ + fflush(stdout); \ + } while (0) +#else +#define ETHASH_CRITICAL(...) +#endif + +/** + * Prepares io for ethash + * + * Create the DAG directory and the DAG file if they don't exist. + * + * @param[in] dirname A null terminated c-string of the path of the ethash + * data directory. If it does not exist it's created. + * @param[in] seedhash The seedhash of the current block number, used in the + * naming of the file as can be seen from the spec at: + * https://github.com/ethereum/wiki/wiki/Ethash-DAG + * @param[out] output_file If there was no failure then this will point to an open + * file descriptor. User is responsible for closing it. + * In the case of memo match then the file is open on read + * mode, while on the case of mismatch a new file is created + * on write mode + * @param[in] file_size The size that the DAG file should have on disk + * @param[out] force_create If true then there is no check to see if the file + * already exists + * @return For possible return values @see enum ethash_io_rc + */ +enum ethash_io_rc ethash_io_prepare( + char const* dirname, + ethash_h256_t const seedhash, + FILE** output_file, + uint64_t file_size, + bool force_create +); + +/** + * An fopen wrapper for no-warnings crossplatform fopen. + * + * Msvc compiler considers fopen to be insecure and suggests to use their + * alternative. This is a wrapper for this alternative. Another way is to + * #define _CRT_SECURE_NO_WARNINGS, but disabling all security warnings does + * not sound like a good idea. + * + * @param file_name The path to the file to open + * @param mode Opening mode. Check fopen() + * @return The FILE* or NULL in failure + */ +FILE* ethash_fopen(char const* file_name, char const* mode); + +/** + * An strncat wrapper for no-warnings crossplatform strncat. + * + * Msvc compiler considers strncat to be insecure and suggests to use their + * alternative. This is a wrapper for this alternative. Another way is to + * #define _CRT_SECURE_NO_WARNINGS, but disabling all security warnings does + * not sound like a good idea. + * + * @param des Destination buffer + * @param dest_size Maximum size of the destination buffer. This is the + * extra argument for the MSVC secure strncat + * @param src Souce buffer + * @param count Number of bytes to copy from source + * @return If all is well returns the dest buffer. If there is an + * error returns NULL + */ +char* ethash_strncat(char* dest, size_t dest_size, char const* src, size_t count); + +/** + * A cross-platform mkdir wrapper to create a directory or assert it's there + * + * @param dirname The full path of the directory to create + * @return true if the directory was created or if it already + * existed + */ +bool ethash_mkdir(char const* dirname); + +/** + * Get a file's size + * + * @param[in] f The open file stream whose size to get + * @param[out] size Pass a size_t by reference to contain the file size + * @return true in success and false if there was a failure + */ +bool ethash_file_size(FILE* f, size_t* ret_size); + +/** + * Get a file descriptor number from a FILE stream + * + * @param f The file stream whose fd to get + * @return Platform specific fd handler + */ +int ethash_fileno(FILE* f); + +/** + * Create the filename for the DAG. + * + * @param dirname The directory name in which the DAG file should reside + * If it does not end with a directory separator it is appended. + * @param filename The actual name of the file + * @param filename_length The length of the filename in bytes + * @return A char* containing the full name. User must deallocate. + */ +char* ethash_io_create_filename( + char const* dirname, + char const* filename, + size_t filename_length +); + +/** + * Gets the default directory name for the DAG depending on the system + * + * The spec defining this directory is here: https://github.com/ethereum/wiki/wiki/Ethash-DAG + * + * @param[out] strbuf A string buffer of sufficient size to keep the + * null termninated string of the directory name + * @param[in] buffsize Size of @a strbuf in bytes + * @return true for success and false otherwise + */ +bool ethash_get_default_dirname(char* strbuf, size_t buffsize); + +static inline bool ethash_io_mutable_name( + uint32_t revision, + ethash_h256_t const* seed_hash, + char* output +) +{ + uint64_t hash = *((uint64_t*)seed_hash); +#if LITTLE_ENDIAN == BYTE_ORDER + hash = ethash_swap_u64(hash); +#endif + return snprintf(output, DAG_MUTABLE_NAME_MAX_SIZE, "full-R%u-%016" PRIx64, revision, hash) >= 0; +} + +#ifdef __cplusplus +} +#endif |