67 lines
1.6 KiB
Plaintext
67 lines
1.6 KiB
Plaintext
#
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# For a description of the syntax of this configuration file,
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# see the file kconfig-language.txt in the NuttX tools repository.
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#
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config LIBC_LZF
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bool "LZF compression"
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default n
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---help---
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Enable the LZF compression library from Marc Alexander Lehmann
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if LIBC_LZF
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choice
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prompt "Compression options"
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default LIBC_LZF_SMALL
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---help---
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Trade-offs between faster and smaller compression. These sections
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have no effect on decompression.
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config LIBC_LZF_SMALL
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bool "Better compression"
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config LIBC_LZF_FAST
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bool "Faster compression"
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config LIBC_LZF_FASTEST
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bool "Fastest compression"
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endchoice # Compression options
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config LIBC_LZF_HLOG
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int "Log2 Hash table size"
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default 13
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range 1 22
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---help---
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Size of hashtable is (1 << HLOG) * sizeof (char *). Decompression is
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independent of the hash table size the difference between 15 and 14 is
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very small for small blocks (and 14 is usually a bit faster). For a
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low-memory/faster configuration, use HLOG == 13; For best compression,
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use 15 or 16 (or more, up to 22).
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Memory usage for the hash table will be approximately:
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4 * (1 << CONFIG_LIBC_LZF_HLOG)
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For the default setting of 13, this is 32Kb. A setting of 12 would
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be half that or about 16Kb.
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The application calling lzf_compress() must provide the hash table to
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the compresser and may allocate that memory in the most efficient way
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for the application.
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#ifndef HLOG
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# define HLOG 13
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#endif
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config LIBC_LZF_ALIGN
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bool "Strict alignment"
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default y
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---help---
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Unconditionally aligning does not cost very much, so do it if unsure.
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endif # LIBC_LZF
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