a12a8a71bb
The goal is to solve confusion of the "All rights reserved" for licensing
code under an open-source license.
The phrase "All rights reserved" comes from a historical convention that
required this phrase for the copyright protection to apply. This convention
is no longer relevant.
However, even though the phrase has no meaning in establishing the copyright
it has not lost meaning in terms of licensing.
This change makes it so code under the Blender Foundation copyright does
not use "all rights reserved". This is also how the GPL license itself
states how to apply it to the source code:
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This program is free software ...
This change does not change copyright notice in cases when the copyright
is dual (BF and an author), or just an author of the code. It also does
mot change copyright which is inherited from NaN Holding BV as it needs
some further investigation about what is the proper way to handle it.
130 lines
3.0 KiB
C
130 lines
3.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later
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* Copyright 2004-2021 Blender Foundation */
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/** \file
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* \ingroup bli
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*/
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#include <string.h>
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#include "BLI_blenlib.h"
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#include "BLI_filereader.h"
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#include "BLI_mmap.h"
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#include "MEM_guardedalloc.h"
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/* This file implements both memory-backed and memory-mapped-file-backed reading. */
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typedef struct {
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FileReader reader;
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const char *data;
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BLI_mmap_file *mmap;
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size_t length;
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} MemoryReader;
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static ssize_t memory_read_raw(FileReader *reader, void *buffer, size_t size)
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{
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MemoryReader *mem = (MemoryReader *)reader;
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/* Don't read more bytes than there are available in the buffer. */
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size_t readsize = MIN2(size, (size_t)(mem->length - mem->reader.offset));
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memcpy(buffer, mem->data + mem->reader.offset, readsize);
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mem->reader.offset += readsize;
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return readsize;
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}
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static off64_t memory_seek(FileReader *reader, off64_t offset, int whence)
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{
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MemoryReader *mem = (MemoryReader *)reader;
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off64_t new_pos;
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if (whence == SEEK_CUR) {
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new_pos = mem->reader.offset + offset;
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}
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else if (whence == SEEK_SET) {
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new_pos = offset;
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}
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else if (whence == SEEK_END) {
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new_pos = mem->length + offset;
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}
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else {
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return -1;
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}
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if (new_pos < 0 || new_pos > mem->length) {
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return -1;
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}
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mem->reader.offset = new_pos;
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return mem->reader.offset;
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}
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static void memory_close_raw(FileReader *reader)
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{
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MEM_freeN(reader);
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}
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FileReader *BLI_filereader_new_memory(const void *data, size_t len)
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{
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MemoryReader *mem = MEM_callocN(sizeof(MemoryReader), __func__);
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mem->data = (const char *)data;
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mem->length = len;
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mem->reader.read = memory_read_raw;
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mem->reader.seek = memory_seek;
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mem->reader.close = memory_close_raw;
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return (FileReader *)mem;
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}
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/* Memory-mapped file reading.
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* By using `mmap()`, we can map a file so that it can be treated like normal memory,
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* meaning that we can just read from it with `memcpy()` etc.
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* This avoids system call overhead and can significantly speed up file loading.
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*/
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static ssize_t memory_read_mmap(FileReader *reader, void *buffer, size_t size)
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{
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MemoryReader *mem = (MemoryReader *)reader;
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/* Don't read more bytes than there are available in the buffer. */
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size_t readsize = MIN2(size, (size_t)(mem->length - mem->reader.offset));
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if (!BLI_mmap_read(mem->mmap, buffer, mem->reader.offset, readsize)) {
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return 0;
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}
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mem->reader.offset += readsize;
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return readsize;
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}
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static void memory_close_mmap(FileReader *reader)
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{
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MemoryReader *mem = (MemoryReader *)reader;
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BLI_mmap_free(mem->mmap);
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MEM_freeN(mem);
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}
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FileReader *BLI_filereader_new_mmap(int filedes)
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{
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BLI_mmap_file *mmap = BLI_mmap_open(filedes);
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if (mmap == NULL) {
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return NULL;
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}
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MemoryReader *mem = MEM_callocN(sizeof(MemoryReader), __func__);
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mem->mmap = mmap;
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mem->length = BLI_lseek(filedes, 0, SEEK_END);
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mem->reader.read = memory_read_mmap;
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mem->reader.seek = memory_seek;
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mem->reader.close = memory_close_mmap;
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return (FileReader *)mem;
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}
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