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![Richard Purdie](/assets/img/avatar_default.png)
Add some casts to the LZO compression algorithm after they were removed during cleanup and shouldn't have been. Signed-off-by: Richard Purdie <rpurdie@openedhand.com> Cc: Edward Shishkin <edward@namesys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
226 lines
4.3 KiB
C
226 lines
4.3 KiB
C
/*
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* LZO1X Compressor from MiniLZO
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*
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* Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com>
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*
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* The full LZO package can be found at:
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* http://www.oberhumer.com/opensource/lzo/
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*
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* Changed for kernel use by:
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* Nitin Gupta <nitingupta910@gmail.com>
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* Richard Purdie <rpurdie@openedhand.com>
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/lzo.h>
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#include <asm/unaligned.h>
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#include "lzodefs.h"
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static noinline size_t
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_lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
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unsigned char *out, size_t *out_len, void *wrkmem)
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{
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const unsigned char * const in_end = in + in_len;
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const unsigned char * const ip_end = in + in_len - M2_MAX_LEN - 5;
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const unsigned char ** const dict = wrkmem;
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const unsigned char *ip = in, *ii = ip;
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const unsigned char *end, *m, *m_pos;
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size_t m_off, m_len, dindex;
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unsigned char *op = out;
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ip += 4;
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for (;;) {
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dindex = ((size_t)(0x21 * DX3(ip, 5, 5, 6)) >> 5) & D_MASK;
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m_pos = dict[dindex];
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if (m_pos < in)
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goto literal;
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if (ip == m_pos || ((size_t)(ip - m_pos) > M4_MAX_OFFSET))
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goto literal;
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m_off = ip - m_pos;
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if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
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goto try_match;
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dindex = (dindex & (D_MASK & 0x7ff)) ^ (D_HIGH | 0x1f);
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m_pos = dict[dindex];
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if (m_pos < in)
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goto literal;
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if (ip == m_pos || ((size_t)(ip - m_pos) > M4_MAX_OFFSET))
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goto literal;
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m_off = ip - m_pos;
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if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
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goto try_match;
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goto literal;
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try_match:
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if (get_unaligned((const unsigned short *)m_pos)
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== get_unaligned((const unsigned short *)ip)) {
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if (likely(m_pos[2] == ip[2]))
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goto match;
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}
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literal:
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dict[dindex] = ip;
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++ip;
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if (unlikely(ip >= ip_end))
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break;
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continue;
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match:
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dict[dindex] = ip;
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if (ip != ii) {
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size_t t = ip - ii;
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if (t <= 3) {
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op[-2] |= t;
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} else if (t <= 18) {
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*op++ = (t - 3);
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} else {
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size_t tt = t - 18;
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*op++ = 0;
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while (tt > 255) {
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tt -= 255;
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*op++ = 0;
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}
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*op++ = tt;
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}
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do {
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*op++ = *ii++;
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} while (--t > 0);
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}
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ip += 3;
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if (m_pos[3] != *ip++ || m_pos[4] != *ip++
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|| m_pos[5] != *ip++ || m_pos[6] != *ip++
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|| m_pos[7] != *ip++ || m_pos[8] != *ip++) {
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--ip;
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m_len = ip - ii;
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if (m_off <= M2_MAX_OFFSET) {
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m_off -= 1;
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*op++ = (((m_len - 1) << 5)
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| ((m_off & 7) << 2));
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*op++ = (m_off >> 3);
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} else if (m_off <= M3_MAX_OFFSET) {
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m_off -= 1;
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*op++ = (M3_MARKER | (m_len - 2));
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goto m3_m4_offset;
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} else {
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m_off -= 0x4000;
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*op++ = (M4_MARKER | ((m_off & 0x4000) >> 11)
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| (m_len - 2));
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goto m3_m4_offset;
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}
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} else {
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end = in_end;
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m = m_pos + M2_MAX_LEN + 1;
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while (ip < end && *m == *ip) {
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m++;
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ip++;
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}
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m_len = ip - ii;
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if (m_off <= M3_MAX_OFFSET) {
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m_off -= 1;
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if (m_len <= 33) {
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*op++ = (M3_MARKER | (m_len - 2));
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} else {
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m_len -= 33;
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*op++ = M3_MARKER | 0;
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goto m3_m4_len;
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}
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} else {
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m_off -= 0x4000;
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if (m_len <= M4_MAX_LEN) {
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*op++ = (M4_MARKER
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| ((m_off & 0x4000) >> 11)
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| (m_len - 2));
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} else {
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m_len -= M4_MAX_LEN;
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*op++ = (M4_MARKER
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| ((m_off & 0x4000) >> 11));
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m3_m4_len:
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while (m_len > 255) {
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m_len -= 255;
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*op++ = 0;
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}
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*op++ = (m_len);
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}
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}
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m3_m4_offset:
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*op++ = ((m_off & 63) << 2);
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*op++ = (m_off >> 6);
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}
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ii = ip;
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if (unlikely(ip >= ip_end))
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break;
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}
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*out_len = op - out;
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return in_end - ii;
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}
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int lzo1x_1_compress(const unsigned char *in, size_t in_len, unsigned char *out,
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size_t *out_len, void *wrkmem)
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{
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const unsigned char *ii;
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unsigned char *op = out;
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size_t t;
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if (unlikely(in_len <= M2_MAX_LEN + 5)) {
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t = in_len;
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} else {
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t = _lzo1x_1_do_compress(in, in_len, op, out_len, wrkmem);
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op += *out_len;
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}
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if (t > 0) {
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ii = in + in_len - t;
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if (op == out && t <= 238) {
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*op++ = (17 + t);
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} else if (t <= 3) {
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op[-2] |= t;
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} else if (t <= 18) {
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*op++ = (t - 3);
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} else {
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size_t tt = t - 18;
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*op++ = 0;
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while (tt > 255) {
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tt -= 255;
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*op++ = 0;
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}
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*op++ = tt;
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}
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do {
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*op++ = *ii++;
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} while (--t > 0);
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}
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*op++ = M4_MARKER | 1;
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*op++ = 0;
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*op++ = 0;
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*out_len = op - out;
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return LZO_E_OK;
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}
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EXPORT_SYMBOL_GPL(lzo1x_1_compress);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("LZO1X-1 Compressor");
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