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<html><head><title>dlib C++ Library - inflate.h</title></head><body bgcolor='white'><pre> |
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<font color='#009900'>/* inflate.h -- internal inflate state definition |
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* Copyright (C) 1995-2009 Mark Adler |
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* For conditions of distribution and use, see copyright notice in zlib.h |
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*/</font> |
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<font color='#009900'>/* WARNING: this file should *not* be used by applications. It is |
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part of the implementation of the compression library and is |
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subject to change. Applications should only use zlib.h. |
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*/</font> |
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<font color='#009900'>/* define NO_GZIP when compiling if you want to disable gzip header and |
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trailer decoding by inflate(). NO_GZIP would be used to avoid linking in |
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the crc code when it is not needed. For shared libraries, gzip decoding |
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should be left enabled. */</font> |
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<font color='#0000FF'>#ifndef</font> NO_GZIP |
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# define GUNZIP |
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<font color='#0000FF'>#endif</font> |
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<font color='#009900'>/* Possible inflate modes between inflate() calls */</font> |
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<font color='#0000FF'>typedef</font> <font color='#0000FF'>enum</font> <b>{</b> |
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HEAD, <font color='#009900'>/* i: waiting for magic header */</font> |
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FLAGS, <font color='#009900'>/* i: waiting for method and flags (gzip) */</font> |
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TIME, <font color='#009900'>/* i: waiting for modification time (gzip) */</font> |
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OS, <font color='#009900'>/* i: waiting for extra flags and operating system (gzip) */</font> |
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EXLEN, <font color='#009900'>/* i: waiting for extra length (gzip) */</font> |
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EXTRA, <font color='#009900'>/* i: waiting for extra bytes (gzip) */</font> |
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NAME, <font color='#009900'>/* i: waiting for end of file name (gzip) */</font> |
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COMMENT, <font color='#009900'>/* i: waiting for end of comment (gzip) */</font> |
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HCRC, <font color='#009900'>/* i: waiting for header crc (gzip) */</font> |
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DICTID, <font color='#009900'>/* i: waiting for dictionary check value */</font> |
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DICT, <font color='#009900'>/* waiting for inflateSetDictionary() call */</font> |
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TYPE, <font color='#009900'>/* i: waiting for type bits, including last-flag bit */</font> |
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TYPEDO, <font color='#009900'>/* i: same, but skip check to exit inflate on new block */</font> |
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STORED, <font color='#009900'>/* i: waiting for stored size (length and complement) */</font> |
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COPY_, <font color='#009900'>/* i/o: same as COPY below, but only first time in */</font> |
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COPY, <font color='#009900'>/* i/o: waiting for input or output to copy stored block */</font> |
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TABLE, <font color='#009900'>/* i: waiting for dynamic block table lengths */</font> |
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LENLENS, <font color='#009900'>/* i: waiting for code length code lengths */</font> |
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CODELENS, <font color='#009900'>/* i: waiting for length/lit and distance code lengths */</font> |
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LEN_, <font color='#009900'>/* i: same as LEN below, but only first time in */</font> |
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LEN, <font color='#009900'>/* i: waiting for length/lit/eob code */</font> |
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LENEXT, <font color='#009900'>/* i: waiting for length extra bits */</font> |
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DIST, <font color='#009900'>/* i: waiting for distance code */</font> |
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DISTEXT, <font color='#009900'>/* i: waiting for distance extra bits */</font> |
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MATCH, <font color='#009900'>/* o: waiting for output space to copy string */</font> |
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LIT, <font color='#009900'>/* o: waiting for output space to write literal */</font> |
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CHECK, <font color='#009900'>/* i: waiting for 32-bit check value */</font> |
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LENGTH, <font color='#009900'>/* i: waiting for 32-bit length (gzip) */</font> |
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DONE, <font color='#009900'>/* finished check, done -- remain here until reset */</font> |
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BAD, <font color='#009900'>/* got a data error -- remain here until reset */</font> |
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MEM, <font color='#009900'>/* got an inflate() memory error -- remain here until reset */</font> |
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SYNC <font color='#009900'>/* looking for synchronization bytes to restart inflate() */</font> |
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<b>}</b> inflate_mode; |
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<font color='#009900'>/* |
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State transitions between above modes - |
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(most modes can go to BAD or MEM on error -- not shown for clarity) |
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Process header: |
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HEAD -> (gzip) or (zlib) or (raw) |
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(gzip) -> FLAGS -> TIME -> OS -> EXLEN -> EXTRA -> NAME -> COMMENT -> |
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HCRC -> TYPE |
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(zlib) -> DICTID or TYPE |
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DICTID -> DICT -> TYPE |
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(raw) -> TYPEDO |
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Read deflate blocks: |
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TYPE -> TYPEDO -> STORED or TABLE or LEN_ or CHECK |
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STORED -> COPY_ -> COPY -> TYPE |
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TABLE -> LENLENS -> CODELENS -> LEN_ |
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LEN_ -> LEN |
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Read deflate codes in fixed or dynamic block: |
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LEN -> LENEXT or LIT or TYPE |
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LENEXT -> DIST -> DISTEXT -> MATCH -> LEN |
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LIT -> LEN |
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Process trailer: |
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CHECK -> LENGTH -> DONE |
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*/</font> |
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<font color='#009900'>/* state maintained between inflate() calls. Approximately 10K bytes. */</font> |
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<font color='#0000FF'>struct</font> <b><a name='inflate_state'></a>inflate_state</b> <b>{</b> |
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inflate_mode mode; <font color='#009900'>/* current inflate mode */</font> |
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<font color='#0000FF'><u>int</u></font> last; <font color='#009900'>/* true if processing last block */</font> |
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<font color='#0000FF'><u>int</u></font> wrap; <font color='#009900'>/* bit 0 true for zlib, bit 1 true for gzip */</font> |
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<font color='#0000FF'><u>int</u></font> havedict; <font color='#009900'>/* true if dictionary provided */</font> |
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<font color='#0000FF'><u>int</u></font> flags; <font color='#009900'>/* gzip header method and flags (0 if zlib) */</font> |
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<font color='#0000FF'><u>unsigned</u></font> dmax; <font color='#009900'>/* zlib header max distance (INFLATE_STRICT) */</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> check; <font color='#009900'>/* protected copy of check value */</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> total; <font color='#009900'>/* protected copy of output count */</font> |
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gz_headerp head; <font color='#009900'>/* where to save gzip header information */</font> |
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<font color='#009900'>/* sliding window */</font> |
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<font color='#0000FF'><u>unsigned</u></font> wbits; <font color='#009900'>/* log base 2 of requested window size */</font> |
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<font color='#0000FF'><u>unsigned</u></font> wsize; <font color='#009900'>/* window size or zero if not using window */</font> |
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<font color='#0000FF'><u>unsigned</u></font> whave; <font color='#009900'>/* valid bytes in the window */</font> |
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<font color='#0000FF'><u>unsigned</u></font> wnext; <font color='#009900'>/* window write index */</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>char</u></font> FAR <font color='#5555FF'>*</font>window; <font color='#009900'>/* allocated sliding window, if needed */</font> |
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<font color='#009900'>/* bit accumulator */</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> hold; <font color='#009900'>/* input bit accumulator */</font> |
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<font color='#0000FF'><u>unsigned</u></font> bits; <font color='#009900'>/* number of bits in "in" */</font> |
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<font color='#009900'>/* for string and stored block copying */</font> |
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<font color='#0000FF'><u>unsigned</u></font> length; <font color='#009900'>/* literal or length of data to copy */</font> |
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<font color='#0000FF'><u>unsigned</u></font> offset; <font color='#009900'>/* distance back to copy string from */</font> |
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<font color='#009900'>/* for table and code decoding */</font> |
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<font color='#0000FF'><u>unsigned</u></font> extra; <font color='#009900'>/* extra bits needed */</font> |
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<font color='#009900'>/* fixed and dynamic code tables */</font> |
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code <font color='#0000FF'>const</font> FAR <font color='#5555FF'>*</font>lencode; <font color='#009900'>/* starting table for length/literal codes */</font> |
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code <font color='#0000FF'>const</font> FAR <font color='#5555FF'>*</font>distcode; <font color='#009900'>/* starting table for distance codes */</font> |
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<font color='#0000FF'><u>unsigned</u></font> lenbits; <font color='#009900'>/* index bits for lencode */</font> |
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<font color='#0000FF'><u>unsigned</u></font> distbits; <font color='#009900'>/* index bits for distcode */</font> |
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<font color='#009900'>/* dynamic table building */</font> |
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<font color='#0000FF'><u>unsigned</u></font> ncode; <font color='#009900'>/* number of code length code lengths */</font> |
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<font color='#0000FF'><u>unsigned</u></font> nlen; <font color='#009900'>/* number of length code lengths */</font> |
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<font color='#0000FF'><u>unsigned</u></font> ndist; <font color='#009900'>/* number of distance code lengths */</font> |
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<font color='#0000FF'><u>unsigned</u></font> have; <font color='#009900'>/* number of code lengths in lens[] */</font> |
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code FAR <font color='#5555FF'>*</font>next; <font color='#009900'>/* next available space in codes[] */</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>short</u></font> lens[<font color='#979000'>320</font>]; <font color='#009900'>/* temporary storage for code lengths */</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>short</u></font> work[<font color='#979000'>288</font>]; <font color='#009900'>/* work area for code table building */</font> |
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code codes[ENOUGH]; <font color='#009900'>/* space for code tables */</font> |
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<font color='#0000FF'><u>int</u></font> sane; <font color='#009900'>/* if false, allow invalid distance too far */</font> |
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<font color='#0000FF'><u>int</u></font> back; <font color='#009900'>/* bits back of last unprocessed length/lit */</font> |
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<font color='#0000FF'><u>unsigned</u></font> was; <font color='#009900'>/* initial length of match */</font> |
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<b>}</b>; |
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</pre></body></html> |
