diff options
Diffstat (limited to 'vendor/github.com/ethereum/ethash/src/libethash/io.c')
| -rw-r--r-- | vendor/github.com/ethereum/ethash/src/libethash/io.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/vendor/github.com/ethereum/ethash/src/libethash/io.c b/vendor/github.com/ethereum/ethash/src/libethash/io.c new file mode 100644 index 000000000..f4db477c2 --- /dev/null +++ b/vendor/github.com/ethereum/ethash/src/libethash/io.c @@ -0,0 +1,119 @@ +/* + 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.c + * @author Lefteris Karapetsas <lefteris@ethdev.com> + * @date 2015 + */ +#include "io.h" +#include <string.h> +#include <stdio.h> +#include <errno.h> + +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 +) +{ + char mutable_name[DAG_MUTABLE_NAME_MAX_SIZE]; + enum ethash_io_rc ret = ETHASH_IO_FAIL; + // reset errno before io calls + errno = 0; + + // assert directory exists + if (!ethash_mkdir(dirname)) { + ETHASH_CRITICAL("Could not create the ethash directory"); + goto end; + } + + ethash_io_mutable_name(ETHASH_REVISION, &seedhash, mutable_name); + char* tmpfile = ethash_io_create_filename(dirname, mutable_name, strlen(mutable_name)); + if (!tmpfile) { + ETHASH_CRITICAL("Could not create the full DAG pathname"); + goto end; + } + + FILE *f; + if (!force_create) { + // try to open the file + f = ethash_fopen(tmpfile, "rb+"); + if (f) { + size_t found_size; + if (!ethash_file_size(f, &found_size)) { + fclose(f); + ETHASH_CRITICAL("Could not query size of DAG file: \"%s\"", tmpfile); + goto free_memo; + } + if (file_size != found_size - ETHASH_DAG_MAGIC_NUM_SIZE) { + fclose(f); + ret = ETHASH_IO_MEMO_SIZE_MISMATCH; + goto free_memo; + } + // compare the magic number, no need to care about endianess since it's local + uint64_t magic_num; + if (fread(&magic_num, ETHASH_DAG_MAGIC_NUM_SIZE, 1, f) != 1) { + // I/O error + fclose(f); + ETHASH_CRITICAL("Could not read from DAG file: \"%s\"", tmpfile); + ret = ETHASH_IO_MEMO_SIZE_MISMATCH; + goto free_memo; + } + if (magic_num != ETHASH_DAG_MAGIC_NUM) { + fclose(f); + ret = ETHASH_IO_MEMO_SIZE_MISMATCH; + goto free_memo; + } + ret = ETHASH_IO_MEMO_MATCH; + goto set_file; + } + } + + // file does not exist, will need to be created + f = ethash_fopen(tmpfile, "wb+"); + if (!f) { + ETHASH_CRITICAL("Could not create DAG file: \"%s\"", tmpfile); + goto free_memo; + } + // make sure it's of the proper size + if (fseek(f, (long int)(file_size + ETHASH_DAG_MAGIC_NUM_SIZE - 1), SEEK_SET) != 0) { + fclose(f); + ETHASH_CRITICAL("Could not seek to the end of DAG file: \"%s\". Insufficient space?", tmpfile); + goto free_memo; + } + if (fputc('\n', f) == EOF) { + fclose(f); + ETHASH_CRITICAL("Could not write in the end of DAG file: \"%s\". Insufficient space?", tmpfile); + goto free_memo; + } + if (fflush(f) != 0) { + fclose(f); + ETHASH_CRITICAL("Could not flush at end of DAG file: \"%s\". Insufficient space?", tmpfile); + goto free_memo; + } + ret = ETHASH_IO_MEMO_MISMATCH; + goto set_file; + + ret = ETHASH_IO_MEMO_MATCH; +set_file: + *output_file = f; +free_memo: + free(tmpfile); +end: + return ret; +} |