mirror of
https://github.com/zerotier/lf.git
synced 2026-05-22 16:24:00 -07:00
Adam Ierymenko
98 lines
2.4 KiB
C
98 lines
2.4 KiB
C
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at https://mozilla.org/MPL/2.0/.
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*
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* (c)2019-2021 ZeroTier, Inc.
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* https://www.zerotier.com/
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*/
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#ifndef ZTLF_MAPPEDFILE_H
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#define ZTLF_MAPPEDFILE_H
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#include "common.h"
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struct ZTLF_MappedFile
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{
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uintptr_t size;
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uintptr_t sizeIncrement;
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void *ptr;
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int fd;
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};
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static inline int ZTLF_MappedFile_Open(struct ZTLF_MappedFile *f,const char *path,const uintptr_t initialSize,const uintptr_t sizeIncrement)
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{
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f->fd = open(path,O_RDWR|O_CREAT,0644);
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if (f->fd < 0)
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return errno;
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int64_t fileSize = (int64_t)lseek(f->fd,0,SEEK_END);
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if (fileSize < 0) {
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close(f->fd);
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return errno;
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}
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if (fileSize < (int64_t)initialSize) {
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if (ftruncate(f->fd,(off_t)initialSize) != 0) {
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close(f->fd);
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return errno;
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}
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f->size = initialSize;
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} else {
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f->size = (uintptr_t)fileSize;
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}
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f->sizeIncrement = sizeIncrement;
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f->ptr = mmap(NULL,(size_t)(f->size),PROT_READ|PROT_WRITE,MAP_FILE|MAP_SHARED,f->fd,0);
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if (!f->ptr) {
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close(f->fd);
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return errno;
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}
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return 0;
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}
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static inline void ZTLF_MappedFile_Close(struct ZTLF_MappedFile *f)
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{
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if (f->ptr) {
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munmap(f->ptr,(size_t)(f->size));
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close(f->fd);
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f->ptr = NULL;
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f->fd = -1;
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}
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}
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static inline void *ZTLF_MappedFile_TryGet(struct ZTLF_MappedFile *f,const uintptr_t at,const uintptr_t len)
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{
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if (likely((at + len) <= f->size)) {
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return (void *)(((uint8_t *)f->ptr) + at);
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}
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return NULL;
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}
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static inline void *ZTLF_MappedFile_Get(struct ZTLF_MappedFile *f,const uintptr_t at,const uintptr_t len)
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{
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if (likely((at + len) <= f->size)) {
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return (void *)(((uint8_t *)f->ptr) + at);
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}
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if (!f->sizeIncrement)
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return NULL;
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const uintptr_t newSize = f->size + f->sizeIncrement;
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munmap(f->ptr,(size_t)(f->size));
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if (ftruncate(f->fd,(off_t)newSize) != 0) {
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f->ptr = mmap(NULL,(size_t)(f->size),PROT_READ|PROT_WRITE,MAP_FILE|MAP_SHARED,f->fd,0);
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if (!f->ptr) {
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//ZTLF_L_fatal("cannot remap mapped file after failed grow attempt: %d (%s)",errno,strerror(errno));
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abort();
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}
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return NULL;
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}
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f->ptr = mmap(NULL,(size_t)(f->size),PROT_READ|PROT_WRITE,MAP_FILE|MAP_SHARED,f->fd,0);
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if (!f->ptr) {
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//ZTLF_L_fatal("cannot remap mapped file after growing file size: %d (%s)",errno,strerror(errno));
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abort();
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}
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f->size = newSize;
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return (void *)(((uint8_t *)f->ptr) + at);
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}
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#endif
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