Files
test2/source/blender/blenloader/intern/readblenentry.cc
Jacques Lucke ed29ab303c Blenloader: extract blenloader core library for use in blendthumb
We recently started using blenloader code in blendthumb to avoid having to
reimplement some parts of .blend file parsing. While this works, it has the side
effect that on Windows referencing blenloader code increased the binary size of
blendthumb from < 1MB to ~75 MB. That happens because this dependency drags
along lots of other code which effectively is unused, but the compiler is unable
to remove it.

There didn't seem to be a simple solution to make msvc optimize the unused code
away. This patch solves the issue by extracting the shared code into a separate
`blenloader_core` module which does not depend on the rest of Blender (except
blenlib). Therefore, using this new module in blendthumb does not drag along all
the other dependencies, bring its file size back down.

In the future, more code may be moved from blenloader to blenloader_core, but
for now I extracted these two headers:
* `BLO_core_bhead.hh`: Various `BHead` types and related parsing functions.
* `BLO_core_blend_header.hh`: Parsing of the header at the beginning of .blend
  files.

Pull Request: https://projects.blender.org/blender/blender/pulls/138371
2025-05-07 04:51:50 +02:00

408 lines
12 KiB
C++

/* SPDX-FileCopyrightText: 2001-2002 NaN Holding BV. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later */
/** \file
* \ingroup blenloader
* `.blend` file reading entry point.
*/
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include "MEM_guardedalloc.h"
#include "BLI_ghash.h"
#include "BLI_linklist.h"
#include "BLI_path_utils.hh" /* Only for assertions. */
#include "BLI_string.h"
#include "BLI_utildefines.h"
#include "DNA_genfile.h"
#include "BKE_asset.hh"
#include "BKE_idtype.hh"
#include "BKE_main.hh"
#include "BKE_preview_image.hh"
#include "BLO_readfile.hh"
#include "readfile.hh"
#include "BLI_sys_types.h" /* Needed for `intptr_t`. */
#ifdef WIN32
# include "BLI_winstuff.h"
#endif
/* Access routines used by file-selector. */
void BLO_datablock_info_free(BLODataBlockInfo *datablock_info)
{
if (datablock_info->free_asset_data) {
BKE_asset_metadata_free(&datablock_info->asset_data);
datablock_info->free_asset_data = false;
}
}
void BLO_datablock_info_linklist_free(LinkNode *datablock_infos)
{
BLI_linklist_free(datablock_infos, [](void *link) {
BLODataBlockInfo *datablock_info = static_cast<BLODataBlockInfo *>(link);
BLO_datablock_info_free(datablock_info);
MEM_freeN(datablock_info);
});
}
BlendHandle *BLO_blendhandle_from_file(const char *filepath, BlendFileReadReport *reports)
{
BlendHandle *bh;
bh = (BlendHandle *)blo_filedata_from_file(filepath, reports);
return bh;
}
BlendHandle *BLO_blendhandle_from_memory(const void *mem,
int memsize,
BlendFileReadReport *reports)
{
BlendHandle *bh;
bh = (BlendHandle *)blo_filedata_from_memory(mem, memsize, reports);
return bh;
}
LinkNode *BLO_blendhandle_get_datablock_names(BlendHandle *bh,
int ofblocktype,
const bool use_assets_only,
int *r_tot_names)
{
FileData *fd = (FileData *)bh;
LinkNode *names = nullptr;
BHead *bhead;
int tot = 0;
for (bhead = blo_bhead_first(fd); bhead; bhead = blo_bhead_next(fd, bhead)) {
if (bhead->code == ofblocktype) {
const char *idname = blo_bhead_id_name(fd, bhead);
if (use_assets_only && blo_bhead_id_asset_data_address(fd, bhead) == nullptr) {
continue;
}
BLI_linklist_prepend(&names, BLI_strdup(idname + 2));
tot++;
}
else if (bhead->code == BLO_CODE_ENDB) {
break;
}
}
*r_tot_names = tot;
return names;
}
LinkNode *BLO_blendhandle_get_datablock_info(BlendHandle *bh,
int ofblocktype,
const bool use_assets_only,
int *r_tot_info_items)
{
FileData *fd = (FileData *)bh;
LinkNode *infos = nullptr;
BHead *bhead;
int tot = 0;
const int sdna_nr_preview_image = DNA_struct_find_with_alias(fd->filesdna, "PreviewImage");
for (bhead = blo_bhead_first(fd); bhead; bhead = blo_bhead_next(fd, bhead)) {
if (bhead->code == BLO_CODE_ENDB) {
break;
}
if (bhead->code == ofblocktype) {
BHead *id_bhead = bhead;
const char *name = blo_bhead_id_name(fd, bhead) + 2;
AssetMetaData *asset_meta_data = blo_bhead_id_asset_data_address(fd, bhead);
const bool is_asset = asset_meta_data != nullptr;
const bool skip_datablock = use_assets_only && !is_asset;
if (skip_datablock) {
continue;
}
BLODataBlockInfo *info = MEM_mallocN<BLODataBlockInfo>(__func__);
/* Lastly, read asset data from the following blocks. */
if (asset_meta_data) {
bhead = blo_read_asset_data_block(fd, bhead, &asset_meta_data);
/* blo_read_asset_data_block() reads all DATA heads and already advances bhead to the
* next non-DATA one. Go back, so the loop doesn't skip the non-DATA head. */
bhead = blo_bhead_prev(fd, bhead);
}
STRNCPY(info->name, name);
info->asset_data = asset_meta_data;
info->free_asset_data = true;
bool has_preview = false;
/* See if we can find a preview in the data of this ID. */
for (BHead *data_bhead = blo_bhead_next(fd, id_bhead); data_bhead->code == BLO_CODE_DATA;
data_bhead = blo_bhead_next(fd, data_bhead))
{
if (data_bhead->SDNAnr == sdna_nr_preview_image) {
has_preview = true;
break;
}
}
info->no_preview_found = !has_preview;
BLI_linklist_prepend(&infos, info);
tot++;
}
}
*r_tot_info_items = tot;
return infos;
}
/**
* Read the preview rects and store in `result`.
*
* `bhead` should point to the block that sourced the `preview_from_file`
* parameter.
* `bhead` parameter is consumed. The correct bhead pointing to the next bhead in the file after
* the preview rects is returned by this function.
* \param fd: The filedata to read the data from.
* \param bhead: should point to the block that sourced the `preview_from_file parameter`.
* bhead is consumed. the new bhead is returned by this function.
* \param result: the Preview Image where the preview rect will be stored.
* \param preview_from_file: The read PreviewImage where the bhead points to. The rects of this
* \return PreviewImage or nullptr when no preview Images have been found. Caller owns the returned
*/
static BHead *blo_blendhandle_read_preview_rects(FileData *fd,
BHead *bhead,
PreviewImage *result,
const PreviewImage *preview_from_file)
{
for (int preview_index = 0; preview_index < NUM_ICON_SIZES; preview_index++) {
if (preview_from_file->rect[preview_index] && preview_from_file->w[preview_index] &&
preview_from_file->h[preview_index])
{
bhead = blo_bhead_next(fd, bhead);
BLI_assert((preview_from_file->w[preview_index] * preview_from_file->h[preview_index] *
sizeof(uint)) == bhead->len);
result->rect[preview_index] = static_cast<uint *>(
BLO_library_read_struct(fd, bhead, "PreviewImage Icon Rect"));
}
else {
/* This should not be needed, but can happen in 'broken' .blend files,
* better handle this gracefully than crashing. */
BLI_assert(preview_from_file->rect[preview_index] == nullptr &&
preview_from_file->w[preview_index] == 0 &&
preview_from_file->h[preview_index] == 0);
result->rect[preview_index] = nullptr;
result->w[preview_index] = result->h[preview_index] = 0;
}
BKE_previewimg_finish(result, preview_index);
}
return bhead;
}
PreviewImage *BLO_blendhandle_get_preview_for_id(BlendHandle *bh,
int ofblocktype,
const char *name)
{
FileData *fd = (FileData *)bh;
bool looking = false;
const int sdna_preview_image = DNA_struct_find_with_alias(fd->filesdna, "PreviewImage");
for (BHead *bhead = blo_bhead_first(fd); bhead; bhead = blo_bhead_next(fd, bhead)) {
if (bhead->code == BLO_CODE_DATA) {
if (looking && bhead->SDNAnr == sdna_preview_image) {
PreviewImage *preview_from_file = static_cast<PreviewImage *>(
BLO_library_read_struct(fd, bhead, "PreviewImage"));
if (preview_from_file == nullptr) {
break;
}
PreviewImage *result = static_cast<PreviewImage *>(MEM_dupallocN(preview_from_file));
result->runtime = MEM_new<blender::bke::PreviewImageRuntime>(__func__);
bhead = blo_blendhandle_read_preview_rects(fd, bhead, result, preview_from_file);
MEM_freeN(preview_from_file);
return result;
}
}
else if (looking || bhead->code == BLO_CODE_ENDB) {
/* We were looking for a preview image, but didn't find any belonging to block. So it doesn't
* exist. */
break;
}
else if (bhead->code == ofblocktype) {
const char *idname = blo_bhead_id_name(fd, bhead);
if (STREQ(&idname[2], name)) {
looking = true;
}
}
}
return nullptr;
}
LinkNode *BLO_blendhandle_get_linkable_groups(BlendHandle *bh)
{
FileData *fd = (FileData *)bh;
GSet *gathered = BLI_gset_ptr_new("linkable_groups gh");
LinkNode *names = nullptr;
BHead *bhead;
for (bhead = blo_bhead_first(fd); bhead; bhead = blo_bhead_next(fd, bhead)) {
if (bhead->code == BLO_CODE_ENDB) {
break;
}
if (BKE_idtype_idcode_is_valid(bhead->code)) {
if (BKE_idtype_idcode_is_linkable(bhead->code)) {
const char *str = BKE_idtype_idcode_to_name(bhead->code);
if (BLI_gset_add(gathered, (void *)str)) {
BLI_linklist_prepend(&names, BLI_strdup(str));
}
}
}
}
BLI_gset_free(gathered, nullptr);
return names;
}
void BLO_blendhandle_close(BlendHandle *bh)
{
FileData *fd = (FileData *)bh;
blo_filedata_free(fd);
}
void BLO_read_invalidate_message(BlendHandle *bh, Main *bmain, const char *message)
{
FileData *fd = reinterpret_cast<FileData *>(bh);
blo_readfile_invalidate(fd, bmain, message);
}
/**********/
BlendFileData *BLO_read_from_file(const char *filepath,
eBLOReadSkip skip_flags,
BlendFileReadReport *reports)
{
BLI_assert(!BLI_path_is_rel(filepath));
BLI_assert(BLI_path_is_abs_from_cwd(filepath));
BlendFileData *bfd = nullptr;
FileData *fd;
fd = blo_filedata_from_file(filepath, reports);
if (fd) {
fd->skip_flags = skip_flags;
bfd = blo_read_file_internal(fd, filepath);
blo_filedata_free(fd);
}
return bfd;
}
BlendFileData *BLO_read_from_memory(const void *mem,
int memsize,
eBLOReadSkip skip_flags,
ReportList *reports)
{
BlendFileData *bfd = nullptr;
FileData *fd;
BlendFileReadReport bf_reports{};
bf_reports.reports = reports;
fd = blo_filedata_from_memory(mem, memsize, &bf_reports);
if (fd) {
fd->skip_flags = skip_flags;
bfd = blo_read_file_internal(fd, "");
blo_filedata_free(fd);
}
return bfd;
}
BlendFileData *BLO_read_from_memfile(Main *oldmain,
const char *filepath,
MemFile *memfile,
const BlendFileReadParams *params,
ReportList *reports)
{
BlendFileData *bfd = nullptr;
FileData *fd;
ListBase old_mainlist;
BlendFileReadReport bf_reports{};
bf_reports.reports = reports;
fd = blo_filedata_from_memfile(memfile, params, &bf_reports);
if (fd) {
fd->skip_flags = eBLOReadSkip(params->skip_flags);
STRNCPY(fd->relabase, filepath);
/* Build old ID map for all old IDs. */
blo_make_old_idmap_from_main(fd, oldmain);
/* Separate linked data from old main. */
blo_split_main(&old_mainlist, oldmain);
fd->old_mainlist = &old_mainlist;
/* Removed packed data from this trick - it's internal data that needs saves. */
/* Store all existing ID caches pointers into a mapping, to allow restoring them into newly
* read IDs whenever possible.
*
* Note that this is only required for local data, since linked data are always re-used
* 'as-is'. */
blo_cache_storage_init(fd, oldmain);
bfd = blo_read_file_internal(fd, filepath);
/* Ensure relinked caches are not freed together with their old IDs. */
blo_cache_storage_old_bmain_clear(fd, oldmain);
/* Still in-use libraries have already been moved from oldmain to new mainlist,
* but oldmain itself shall *never* be 'transferred' to new mainlist! */
BLI_assert(old_mainlist.first == oldmain);
/* That way, libraries (aka mains) we did not reuse in new undone/redone state
* will be cleared together with `oldmain`. */
blo_join_main(&old_mainlist);
blo_filedata_free(fd);
}
return bfd;
}
void BLO_blendfiledata_free(BlendFileData *bfd)
{
if (bfd->main) {
BKE_main_free(bfd->main);
}
if (bfd->user) {
MEM_freeN(bfd->user);
}
MEM_delete(bfd);
}
void BLO_read_do_version_after_setup(Main *new_bmain,
BlendfileLinkAppendContext *lapp_context,
BlendFileReadReport *reports)
{
do_versions_after_setup(new_bmain, lapp_context, reports);
}