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36 lines
1.3 KiB
Text
36 lines
1.3 KiB
Text
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This is a propsal to extend the progs.dat file format without breaking
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backwards compatability. Currently the progs file format header has a
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description simaler to this:
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struct {
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uint32_t version;
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uint32_t crc16;
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....
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uint32_t entfield;
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}
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The obvious notable issue here is version and crc16 are larger than they
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essentially need to be, if we made version and crc16 both uint16_t we can
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give ourselfs 32 bytes (2x16) to store additional data that can be used
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to make smaller progs.dat files.
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I propose a new structual layout like this:
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struct {
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uint16_t version;
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uint16_t flags; /* contains a skip field */
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uint16_t crc16;
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uint16_t skip; /* skiped globals */
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....
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uint32_t entfield;
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}
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about 45% of globals are zero, if we could order them at the top of the
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globals array we can essentially use the skip field to specify how much
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zero globals the engine would have to populate (instead of being stored
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in the actual file itself) flags can specify if the progs.dat file skiped
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globals on the write of the progs.dat file.
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Of course only one bit in the flags would have to be set to specify if the
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file contains a skip field. Which lends itself to the fact that flags could
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later be extended for other things.
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