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Initial implementation of SLXI chunk save/load

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This commit is contained in:
Jonathan G Rennison
2015-08-01 12:24:45 +01:00
parent a3980dc6ba
commit bde094fe01
4 changed files with 299 additions and 35 deletions
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249
src/saveload/extended_ver_sl.cpp
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@@ -7,17 +7,47 @@
* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file extended_ver_sl.cpp Functions related to handling save/load extended version info. */
/** @file extended_ver_sl.cpp Functions related to handling save/load extended version info.
*
* Known extended features are stored in _sl_xv_feature_versions, features which are currently enabled/in use and their versions are stored in the savegame.
* On load, the list of features and their versions are loaded from the savegame. If the savegame contains a feature which is either unknown, or has too high a version,
* loading can be either aborted, or the feature can be ignored if the the feature flags in the savegame indicate that it can be ignored. The savegame may also list any additional
* chunk IDs which are associated with an extended feature, these can be discarded if the feature is discarded.
* This information is stored in the SLXI chunk, the contents of which has the following format:
*
* uint32 chunk version
* uint32 chunk flags
* uint32 number of sub chunks/features
* For each of N sub chunk/feature:
* uint32 feature flags (SlxiSubChunkFlags)
* uint16 feature version
* SLE_STR feature name
* uint32* extra data length [only present iff feature flags & XSCF_EXTRA_DATA_PRESENT]
* N bytes extra data
* uint32* chunk ID list count [only present iff feature flags & XSCF_CHUNK_ID_LIST_PRESENT]
* N x uint32 chunk ID list
*/
#include "../stdafx.h"
#include "../debug.h"
#include "saveload.h"
#include "extended_ver_sl.h"
#include <vector>
#include "../safeguards.h"
uint16 _sl_xv_feature_versions[XSLFI_SIZE]; ///< array of all known feature types and their current versions
bool _sl_is_ext_version; ///< is this an extended savegame version, with more info in the SLXI chunk?
bool _sl_is_faked_ext; ///< is this a faked extended savegame version, with no SLXI chunk?
std::vector<uint32> _sl_xv_discardable_chunk_ids; ///< list of chunks IDs which we can discard if no chunk loader exists
static const uint32 _sl_xv_slxi_chunk_version = 0; ///< current version os SLXI chunk
const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
{ XSLFI_NULL, XSCF_NULL, 0, 0, NULL, NULL, NULL, NULL },// This is the end marker
};
/**
* Extended save/load feature test
*
@@ -26,16 +56,16 @@ std::vector<uint32> _sl_xv_discardable_chunk_ids; ///< list of chunks
* and return the combination of the two tests using the operator defined in the constructor.
* Otherwise just returns the result of the savegame version test
*/
bool ExtendedSaveLoadFeatureTest::IsFeaturePresent(uint16 savegame_version, uint16 savegame_version_from, uint16 savegame_version_to) const
bool SlXvFeatureTest::IsFeaturePresent(uint16 savegame_version, uint16 savegame_version_from, uint16 savegame_version_to) const
{
bool savegame_version_ok = savegame_version >= savegame_version_from && savegame_version <= savegame_version_to;
ExtendedSaveLoadFeatureIndex feature = static_cast<ExtendedSaveLoadFeatureIndex>(GB(this->value, 0, 16));
SlXvFeatureIndex feature = static_cast<SlXvFeatureIndex>(GB(this->value, 0, 16));
if (feature == XSLFI_NULL) return savegame_version_ok;
uint16 min_version = GB(this->value, 16, 16);
uint16 max_version = GB(this->value, 32, 16);
ExtendedSaveLoadFeatureTestOperator op = static_cast<ExtendedSaveLoadFeatureTestOperator>(GB(this->value, 48, 16));
SlXvFeatureTestOperator op = static_cast<SlXvFeatureTestOperator>(GB(this->value, 48, 16));
bool feature_ok = SlXvIsFeaturePresent(feature, min_version, max_version);
switch (op) {
@@ -54,7 +84,7 @@ bool ExtendedSaveLoadFeatureTest::IsFeaturePresent(uint16 savegame_version, uint
/**
* Returns true if @p feature is present and has a version inclusively bounded by @p min_version and @p max_version
*/
bool SlXvIsFeaturePresent(ExtendedSaveLoadFeatureIndex feature, uint16 min_version, uint16 max_version)
bool SlXvIsFeaturePresent(SlXvFeatureIndex feature, uint16 min_version, uint16 max_version)
{
assert(feature < XSLFI_SIZE);
return _sl_xv_feature_versions[feature] >= min_version && _sl_xv_feature_versions[feature] <= max_version;
@@ -65,6 +95,8 @@ bool SlXvIsFeaturePresent(ExtendedSaveLoadFeatureIndex feature, uint16 min_versi
*/
void SlXvResetState()
{
_sl_is_ext_version = false;
_sl_is_faked_ext = false;
memset(_sl_xv_feature_versions, 0, sizeof(_sl_xv_feature_versions));
}
@@ -73,8 +105,6 @@ void SlXvResetState()
*/
void SlXvSetCurrentState()
{
extern bool _sl_is_ext_version;
SlXvResetState();
_sl_is_ext_version = true;
@@ -103,3 +133,208 @@ bool SlXvIsChunkDiscardable(uint32 id)
}
return false;
}
/**
* Writes a chunk ID list string to the savegame, returns the number of chunks written
* In dry run mode, only returns the number of chunk which would have been written
*/
static uint32 WriteChunkIdList(const char *chunk_list, bool dry_run)
{
unsigned int chunk_count = 0; // number of chunks output
unsigned int id_offset = 0; // how far are we into the ID
for (; *chunk_list != 0; chunk_list++) {
if (id_offset == 4) {
assert(*chunk_list == ',');
id_offset = 0;
} else {
if (!dry_run) {
SlWriteByte(*chunk_list);
}
if (id_offset == 3) {
chunk_count++;
}
id_offset++;
}
}
assert(id_offset == 4);
return chunk_count;
}
static void Save_SLXI()
{
SlXvSetCurrentState();
static const SaveLoad _xlsi_sub_chunk_desc[] = {
SLE_VAR(SlxiSubChunkInfo, save_version, SLE_UINT16),
SLE_STR(SlxiSubChunkInfo, name, SLE_STR, 0),
SLE_END()
};
// calculate lengths
uint32 item_count = 0;
uint32 length = 12;
std::vector<uint32> extra_data_lengths;
std::vector<uint32> chunk_counts;
extra_data_lengths.resize(XSLFI_SIZE);
chunk_counts.resize(XSLFI_SIZE);
const SlxiSubChunkInfo *info = _sl_xv_sub_chunk_infos;
for (; info->index != XSLFI_NULL; ++info) {
if (info->save_version > 0) {
item_count++;
length += 4;
length += SlCalcObjLength(info, _xlsi_sub_chunk_desc);
if (info->save_proc) {
uint32 extra_data_length = info->save_proc(info, true);
if (extra_data_length) {
extra_data_lengths[info->index] = extra_data_length;
length += 4 + extra_data_length;
}
}
if (info->chunk_list) {
uint32 chunk_count = WriteChunkIdList(info->chunk_list, true);
if (chunk_count) {
chunk_counts[info->index] = chunk_count;
length += 4 * (1 + chunk_count);
}
}
}
}
// write header
SlSetLength(length);
SlWriteUint32(_sl_xv_slxi_chunk_version); // chunk version
SlWriteUint32(0); // flags
SlWriteUint32(item_count); // item count
// write data
info = _sl_xv_sub_chunk_infos;
for (; info->index != XSLFI_NULL; ++info) {
if (info->save_version > 0) {
SlxiSubChunkFlags flags = info->flags;
assert(!(flags & (XSCF_EXTRA_DATA_PRESENT | XSCF_CHUNK_ID_LIST_PRESENT)));
uint32 extra_data_length = extra_data_lengths[info->index];
uint32 chunk_count = chunk_counts[info->index];
if (extra_data_length > 0) flags |= XSCF_EXTRA_DATA_PRESENT;
if (chunk_count > 0) flags |= XSCF_CHUNK_ID_LIST_PRESENT;
SlWriteUint32(flags);
SlObject(const_cast<SlxiSubChunkInfo *>(info), _xlsi_sub_chunk_desc);
if (extra_data_length > 0) {
SlWriteUint32(extra_data_length);
size_t written = SlGetBytesWritten();
info->save_proc(info, false);
assert(SlGetBytesWritten() == written + extra_data_length);
}
if (chunk_count > 0) {
SlWriteUint32(chunk_count);
size_t written = SlGetBytesWritten();
WriteChunkIdList(info->chunk_list, false);
assert(SlGetBytesWritten() == written + (chunk_count * 4));
}
}
}
}
static void Load_SLXI()
{
if (_sl_is_faked_ext || !_sl_is_ext_version) {
SlErrorCorrupt("SXLI chunk is unexpectedly present");
}
SlXvResetState();
_sl_is_ext_version = true;
uint32 version = SlReadUint32();
if (version > _sl_xv_slxi_chunk_version) SlErrorCorruptFmt("SLXI chunk: version: %u is too new (expected max: %u)", version, _sl_xv_slxi_chunk_version);
uint32 chunk_flags = SlReadUint32();
// flags are not in use yet, reserve for future expansion
if (chunk_flags != 0) SlErrorCorruptFmt("SLXI chunk: unknown chunk header flags: 0x%X", chunk_flags);
char name_buffer[256];
const SaveLoadGlobVarList xlsi_sub_chunk_name_desc[] = {
SLEG_STR(name_buffer, SLE_STRB),
SLEG_END()
};
uint32 item_count = SlReadUint32();
for (uint32 i = 0; i < item_count; i++) {
SlxiSubChunkFlags flags = static_cast<SlxiSubChunkFlags>(SlReadUint32());
uint16 version = SlReadUint16();
SlGlobList(xlsi_sub_chunk_name_desc);
// linearly scan through feature list until found name match
bool found = false;
const SlxiSubChunkInfo *info = _sl_xv_sub_chunk_infos;
for (; info->index != XSLFI_NULL; ++info) {
if (strcmp(name_buffer, info->name) == 0) {
found = true;
break;
}
}
bool discard_chunks = false;
if (found) {
if (version > info->max_version) {
if (flags & XSCF_IGNORABLE_VERSION) {
// version too large but carry on regardless
discard_chunks = true;
if (flags & XSCF_EXTRA_DATA_PRESENT) {
SlSkipBytes(SlReadUint32()); // skip extra data field
}
DEBUG(sl, 1, "SLXI chunk: too large version for feature: '%s', version: %d, max version: %d, ignoring", name_buffer, version, info->max_version);
} else {
SlErrorCorruptFmt("SLXI chunk: too large version for feature: '%s', version: %d, max version: %d", name_buffer, version, info->max_version);
}
} else {
// success path :)
_sl_xv_feature_versions[info->index] = version;
if (flags & XSCF_EXTRA_DATA_PRESENT) {
uint32 extra_data_size = SlReadUint32();
if (extra_data_size) {
if (info->load_proc) {
size_t read = SlGetBytesRead();
info->load_proc(info, extra_data_size);
if (SlGetBytesRead() != read + extra_data_size) {
SlErrorCorruptFmt("SLXI chunk: feature: %s, version: %d, extra data length mismatch", name_buffer, version);
}
} else {
SlErrorCorruptFmt("SLXI chunk: feature: %s, version: %d, unexpectedly includes extra data", name_buffer, version);
}
}
}
DEBUG(sl, 1, "SLXI chunk: found known feature: '%s', version: %d, max version: %d", name_buffer, version, info->max_version);
}
} else {
if (flags & XSCF_IGNORABLE_UNKNOWN) {
// not found but carry on regardless
discard_chunks = true;
if (flags & XSCF_EXTRA_DATA_PRESENT) {
SlSkipBytes(SlReadUint32()); // skip extra data field
}
DEBUG(sl, 1, "SLXI chunk: unknown feature: '%s', version: %d, ignoring", name_buffer, version);
} else {
SlErrorCorruptFmt("SLXI chunk: unknown feature: %s, version: %d", name_buffer, version);
}
}
// at this point the extra data field should have been consumed
// handle chunk ID list field
if (flags & XSCF_CHUNK_ID_LIST_PRESENT) {
uint32 chunk_count = SlReadUint32();
for (uint32 j = 0; j < chunk_count; j++) {
uint32 chunk_id = SlReadUint32();
if (discard_chunks) {
_sl_xv_discardable_chunk_ids.push_back(chunk_id);
DEBUG(sl, 2, "SLXI chunk: unknown feature: '%s', discarding chunk: %c%c%c%c", name_buffer, chunk_id >> 24, chunk_id >> 16, chunk_id >> 8, chunk_id);
}
}
}
}
}
extern const ChunkHandler _version_ext_chunk_handlers[] = {
{ 'SLXI', Save_SLXI, Load_SLXI, NULL, Load_SLXI, CH_RIFF | CH_LAST},
};