diff --git a/lib/uzlib/defl_static.c b/lib/uzlib/defl_static.c index 89b5e1aa5f..529055ae84 100644 --- a/lib/uzlib/defl_static.c +++ b/lib/uzlib/defl_static.c @@ -10,6 +10,9 @@ Delchev, Andreas Schultz, Jeroen Massar, Wez Furlong, Nicolas Barry, Justin Bradford, Ben Harris, Malcolm Smith, Ahmad Khalifa, Markus Kuhn, Colin Watson, and CORE SDI S.A. +Optimised for MicroPython: +Copyright (c) 2023 by Jim Mussared + Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, @@ -55,152 +58,44 @@ static void outbits(struct Outbuf *out, unsigned long bits, int nbits) out->outbits |= bits << out->noutbits; out->noutbits += nbits; while (out->noutbits >= 8) { - out->dest_write_cb(out, out->outbits & 0xFF); + out->dest_write_cb(out->dest_write_data, out->outbits & 0xFF); out->outbits >>= 8; out->noutbits -= 8; } } -static const unsigned char mirrorbytes[256] = { - 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, - 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, - 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, - 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, - 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, - 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, - 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, - 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, - 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, - 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, - 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, - 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, - 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, - 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, - 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, - 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, - 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, - 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, - 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, - 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, - 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, - 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, - 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, - 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, - 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, - 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, - 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, - 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, - 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, - 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, - 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, - 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff, +static const unsigned char mirrornibbles[16] = { + 0x0, 0x8, 0x4, 0xc, 0x2, 0xa, 0x6, 0xe, + 0x1, 0x9, 0x5, 0xd, 0x3, 0xb, 0x7, 0xf, }; -typedef struct { - uint8_t extrabits; - uint8_t min, max; -} len_coderecord; +static unsigned int mirrorbyte(unsigned int b) { + return mirrornibbles[b & 0xf] << 4 | mirrornibbles[b >> 4]; +} -typedef struct { - uint8_t code, extrabits; - uint16_t min, max; -} dist_coderecord; - -#define TO_LCODE(x, y) x - 3, y - 3 -#define FROM_LCODE(x) (x + 3) - -static const len_coderecord lencodes[] = { - {0, TO_LCODE(3, 3)}, - {0, TO_LCODE(4, 4)}, - {0, TO_LCODE(5, 5)}, - {0, TO_LCODE(6, 6)}, - {0, TO_LCODE(7, 7)}, - {0, TO_LCODE(8, 8)}, - {0, TO_LCODE(9, 9)}, - {0, TO_LCODE(10, 10)}, - {1, TO_LCODE(11, 12)}, - {1, TO_LCODE(13, 14)}, - {1, TO_LCODE(15, 16)}, - {1, TO_LCODE(17, 18)}, - {2, TO_LCODE(19, 22)}, - {2, TO_LCODE(23, 26)}, - {2, TO_LCODE(27, 30)}, - {2, TO_LCODE(31, 34)}, - {3, TO_LCODE(35, 42)}, - {3, TO_LCODE(43, 50)}, - {3, TO_LCODE(51, 58)}, - {3, TO_LCODE(59, 66)}, - {4, TO_LCODE(67, 82)}, - {4, TO_LCODE(83, 98)}, - {4, TO_LCODE(99, 114)}, - {4, TO_LCODE(115, 130)}, - {5, TO_LCODE(131, 162)}, - {5, TO_LCODE(163, 194)}, - {5, TO_LCODE(195, 226)}, - {5, TO_LCODE(227, 257)}, - {0, TO_LCODE(258, 258)}, -}; - -static const dist_coderecord distcodes[] = { - {0, 0, 1, 1}, - {1, 0, 2, 2}, - {2, 0, 3, 3}, - {3, 0, 4, 4}, - {4, 1, 5, 6}, - {5, 1, 7, 8}, - {6, 2, 9, 12}, - {7, 2, 13, 16}, - {8, 3, 17, 24}, - {9, 3, 25, 32}, - {10, 4, 33, 48}, - {11, 4, 49, 64}, - {12, 5, 65, 96}, - {13, 5, 97, 128}, - {14, 6, 129, 192}, - {15, 6, 193, 256}, - {16, 7, 257, 384}, - {17, 7, 385, 512}, - {18, 8, 513, 768}, - {19, 8, 769, 1024}, - {20, 9, 1025, 1536}, - {21, 9, 1537, 2048}, - {22, 10, 2049, 3072}, - {23, 10, 3073, 4096}, - {24, 11, 4097, 6144}, - {25, 11, 6145, 8192}, - {26, 12, 8193, 12288}, - {27, 12, 12289, 16384}, - {28, 13, 16385, 24576}, - {29, 13, 24577, 32768}, -}; +static int int_log2(int x) { + int r = 0; + while (x >>= 1) { + ++r; + } + return r; +} void zlib_literal(struct Outbuf *out, unsigned char c) { - if (out->comp_disabled) { - /* - * We're in an uncompressed block, so just output the byte. - */ - outbits(out, c, 8); - return; - } - if (c <= 143) { /* 0 through 143 are 8 bits long starting at 00110000. */ - outbits(out, mirrorbytes[0x30 + c], 8); + outbits(out, mirrorbyte(0x30 + c), 8); } else { /* 144 through 255 are 9 bits long starting at 110010000. */ - outbits(out, 1 + 2 * mirrorbytes[0x90 - 144 + c], 9); + outbits(out, 1 + 2 * mirrorbyte(0x90 - 144 + c), 9); } } void zlib_match(struct Outbuf *out, int distance, int len) { - const dist_coderecord *d; - const len_coderecord *l; - int i, j, k; - int lcode; - - assert(!out->comp_disabled); + assert(distance >= 1 && distance <= 32768); + distance -= 1; while (len > 0) { int thislen; @@ -218,73 +113,56 @@ void zlib_match(struct Outbuf *out, int distance, int len) thislen = (len > 260 ? 258 : len <= 258 ? len : len - 3); len -= thislen; - /* - * Binary-search to find which length code we're - * transmitting. - */ - i = -1; - j = sizeof(lencodes) / sizeof(*lencodes); - while (1) { - assert(j - i >= 2); - k = (j + i) / 2; - if (thislen < FROM_LCODE(lencodes[k].min)) - j = k; - else if (thislen > FROM_LCODE(lencodes[k].max)) - i = k; - else { - l = &lencodes[k]; - break; /* found it! */ - } - } + assert(thislen >= 3 && thislen <= 258); - lcode = l - lencodes + 257; + thislen -= 3; + int lcode = 28; + int x = int_log2(thislen); + int y; + if (thislen < 255) { + if (x) { + --x; + } + y = (thislen >> (x ? x - 1 : 0)) & 3; + lcode = x * 4 + y; + } /* * Transmit the length code. 256-279 are seven bits * starting at 0000000; 280-287 are eight bits starting at * 11000000. */ - if (lcode <= 279) { - outbits(out, mirrorbytes[(lcode - 256) * 2], 7); + if (lcode <= 22) { + outbits(out, mirrorbyte((lcode + 1) * 2), 7); } else { - outbits(out, mirrorbytes[0xc0 - 280 + lcode], 8); + outbits(out, mirrorbyte(lcode + 169), 8); } /* * Transmit the extra bits. */ - if (l->extrabits) - outbits(out, thislen - FROM_LCODE(l->min), l->extrabits); - - /* - * Binary-search to find which distance code we're - * transmitting. - */ - i = -1; - j = sizeof(distcodes) / sizeof(*distcodes); - while (1) { - assert(j - i >= 2); - k = (j + i) / 2; - if (distance < distcodes[k].min) - j = k; - else if (distance > distcodes[k].max) - i = k; - else { - d = &distcodes[k]; - break; /* found it! */ - } + if (thislen < 255 && x > 1) { + int extrabits = x - 1; + int lmin = (thislen >> extrabits) << extrabits; + outbits(out, thislen - lmin, extrabits); } + x = int_log2(distance); + y = (distance >> (x ? x - 1 : 0)) & 1; + /* * Transmit the distance code. Five bits starting at 00000. */ - outbits(out, mirrorbytes[d->code * 8], 5); + outbits(out, mirrorbyte((x * 2 + y) * 8), 5); /* * Transmit the extra bits. */ - if (d->extrabits) - outbits(out, distance - d->min, d->extrabits); + if (x > 1) { + int dextrabits = x - 1; + int dmin = (distance >> dextrabits) << dextrabits; + outbits(out, distance - dmin, dextrabits); + } } } diff --git a/lib/uzlib/defl_static.h b/lib/uzlib/defl_static.h index 94741c97fd..7329de36ef 100644 --- a/lib/uzlib/defl_static.h +++ b/lib/uzlib/defl_static.h @@ -32,10 +32,9 @@ struct Outbuf { void *dest_write_data; - void (*dest_write_cb)(struct Outbuf *outbuf, uint8_t byte); + void (*dest_write_cb)(void *data, uint8_t byte); unsigned long outbits; int noutbits; - int comp_disabled; }; void zlib_start_block(struct Outbuf *ctx);