/* Copyright (C) 2001-2020 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied,
   modified or distributed except as expressly authorized under the terms
   of the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
   CA 94945, U.S.A., +1(415)492-9861, for further information.
*/


/* Utilities for Ghostscript library */

#include "string_.h"
#include "memory_.h"
#include "gstypes.h"
#include "gserrors.h"
#include "gsmemory.h"		/* for init procedure */
#include "gsrect.h"		/* for prototypes */
#include "gsuid.h"
#include "gsutil.h"		/* for prototypes */

/* ------ Unique IDs ------ */

ulong
gs_next_ids(const gs_memory_t *mem, uint count)
{
    gs_lib_ctx_core_t *core = mem->gs_lib_ctx->core;
    ulong id = core->gs_next_id;

    core->gs_next_id += count;
    return id;
}

/* ------ Memory utilities ------ */

/* Transpose an 8 x 8 block of bits.  line_size is the raster of */
/* the input data.  dist is the distance between output bytes. */

void
memflip8x8(const byte * inp, int line_size, byte * outp, int dist)
{
    uint aceg, bdfh;

    {
        const byte *ptr4 = inp + (line_size << 2);
        const int ls2 = line_size << 1;

        aceg = ((uint)*inp) | ((uint)inp[ls2] << 8) |
            ((uint)*ptr4 << 16) | ((uint)ptr4[ls2] << 24);
        inp += line_size, ptr4 += line_size;
        bdfh = ((uint)*inp) | ((uint)inp[ls2] << 8) |
            ((uint)*ptr4 << 16) | ((uint)ptr4[ls2] << 24);
    }

    /* Check for all 8 bytes being the same. */
    /* This is especially worth doing for the case where all are zero. */
    if (aceg == bdfh && (aceg >> 8) == (aceg & 0xffffff)) {
        if (aceg == 0 || aceg == 0xffffffff)
            goto store;
        *outp = (byte)-(int)((aceg >> 7) & 1);
        outp[dist] = (byte)-(int)((aceg >> 6) & 1);
        outp += dist << 1;
        *outp = (byte)-(int)((aceg >> 5) & 1);
        outp[dist] = (byte)-(int)((aceg >> 4) & 1);
        outp += dist << 1;
        *outp = (byte)-(int)((aceg >> 3) & 1);
        outp[dist] = (byte)-(int)((aceg >> 2) & 1);
        outp += dist << 1;
        *outp = (byte)-(int)((aceg >> 1) & 1);
        outp[dist] = (byte)-(int)(aceg & 1);
        return;
    } {
        register uint temp;

/* Transpose a block of bits between registers. */
#define TRANSPOSE(r,s,mask,shift)\
  (r ^= (temp = ((s >> shift) ^ r) & mask),\
   s ^= temp << shift)

/* Transpose blocks of 4 x 4 */
        TRANSPOSE(aceg, aceg, 0x00000f0f, 20);
        TRANSPOSE(bdfh, bdfh, 0x00000f0f, 20);

/* Transpose blocks of 2 x 2 */
        TRANSPOSE(aceg, aceg, 0x00330033, 10);
        TRANSPOSE(bdfh, bdfh, 0x00330033, 10);

/* Transpose blocks of 1 x 1 */
        TRANSPOSE(aceg, bdfh, 0x55555555, 1);

#undef TRANSPOSE
    }

  store:
    *outp = (byte)aceg;
    outp[dist] = (byte)bdfh;
    outp += dist << 1;
    *outp = (byte)(aceg >>= 8);
    outp[dist] = (byte)(bdfh >>= 8);
    outp += dist << 1;
    *outp = (byte)(aceg >>= 8);
    outp[dist] = (byte)(bdfh >>= 8);
    outp += dist << 1;
    *outp = (byte)(aceg >> 8);
    outp[dist] = (byte)(bdfh >> 8);
}

#ifdef PACIFY_VALGRIND
void
memflip8x8_eol(const byte * inp, int line_size, byte * outp, int dist, int bits)
{
    uint aceg, bdfh;
    uint mask;

    {
        const byte *ptr4 = inp + (line_size << 2);
        const int ls2 = line_size << 1;

        aceg = ((uint)*inp) | ((uint)inp[ls2] << 8) |
            ((uint)*ptr4 << 16) | ((uint)ptr4[ls2] << 24);
        inp += line_size, ptr4 += line_size;
        bdfh = ((uint)*inp) | ((uint)inp[ls2] << 8) |
            ((uint)*ptr4 << 16) | ((uint)ptr4[ls2] << 24);
    }

    /* Keep just the defined bits */
    mask = (0xff00>>(bits&7)) & 0xff;
    mask |= mask<<8;
    mask |= mask<<16;
    aceg &= mask;
    bdfh &= mask;

    /* Check for all 8 bytes being the same. */
    /* This is especially worth doing for the case where all are zero. */
    if (aceg == bdfh && (aceg >> 8) == (aceg & 0xffffff)) {
        if (aceg == 0 || aceg == 0xffffffff)
            goto store;
        *outp = (byte)-(int)((aceg >> 7) & 1);
        outp[dist] = (byte)-(int)((aceg >> 6) & 1);
        outp += dist << 1;
        *outp = (byte)-(int)((aceg >> 5) & 1);
        outp[dist] = (byte)-(int)((aceg >> 4) & 1);
        outp += dist << 1;
        *outp = (byte)-(int)((aceg >> 3) & 1);
        outp[dist] = (byte)-(int)((aceg >> 2) & 1);
        outp += dist << 1;
        *outp = (byte)-(int)((aceg >> 1) & 1);
        outp[dist] = (byte)-(int)(aceg & 1);
        return;
    } {
        register uint temp;

/* Transpose a block of bits between registers. */
#define TRANSPOSE(r,s,mask,shift)\
  (r ^= (temp = ((s >> shift) ^ r) & mask),\
   s ^= temp << shift)

/* Transpose blocks of 4 x 4 */
        TRANSPOSE(aceg, aceg, 0x00000f0f, 20);
        TRANSPOSE(bdfh, bdfh, 0x00000f0f, 20);

/* Transpose blocks of 2 x 2 */
        TRANSPOSE(aceg, aceg, 0x00330033, 10);
        TRANSPOSE(bdfh, bdfh, 0x00330033, 10);

/* Transpose blocks of 1 x 1 */
        TRANSPOSE(aceg, bdfh, 0x55555555, 1);

#undef TRANSPOSE
    }

  store:
    *outp = (byte)aceg;
    outp[dist] = (byte)bdfh;
    outp += dist << 1;
    *outp = (byte)(aceg >>= 8);
    outp[dist] = (byte)(bdfh >>= 8);
    outp += dist << 1;
    *outp = (byte)(aceg >>= 8);
    outp[dist] = (byte)(bdfh >>= 8);
    outp += dist << 1;
    *outp = (byte)(aceg >> 8);
    outp[dist] = (byte)(bdfh >> 8);
}
#endif

/* Get an unsigned, big-endian 32-bit value. */
ulong
get_u32_msb(const byte *p)
{
    return ((uint)p[0] << 24) + ((uint)p[1] << 16) + ((uint)p[2] << 8) + p[3];
}

/* Put an unsigned, big-endian 32-bit value. */
void
put_u32_msb(byte *p, const ulong n, const int offs)
{
    (p + offs)[0] = n >> 24 & 255;
    (p + offs)[1] = n >> 16 & 255;
    (p + offs)[2] = n >> 8  & 255;
    (p + offs)[3] = n & 255;
}

/* ------ String utilities ------ */

/* Compare two strings, returning -1 if the first is less, */
/* 0 if they are equal, and 1 if first is greater. */
/* We can't use memcmp, because we always use unsigned characters. */
int
bytes_compare(const byte * s1, uint len1, const byte * s2, uint len2)
{
    register uint len = len1;

    if (len2 < len)
        len = len2;
    {
        register const byte *p1 = s1;
        register const byte *p2 = s2;

        while (len--)
            if (*p1++ != *p2++)
                return (p1[-1] < p2[-1] ? -1 : 1);
    }
    /* Now check for differing lengths */
    return (len1 == len2 ? 0 : len1 < len2 ? -1 : 1);
}

/* Test whether a string matches a pattern with wildcards. */
/* '*' = any substring, '?' = any character, '\' quotes next character. */
const string_match_params string_match_params_default = {
    '*', '?', '\\', false, false
};

bool
string_match(const byte * str, uint len, const byte * pstr, uint plen,
             register const string_match_params * psmp)
{
    const byte *pback = 0;
    const byte *spback = 0;	/* initialized only to pacify gcc */
    const byte *p = pstr, *pend = pstr + plen;
    const byte *sp = str, *spend = str + len;

    if (psmp == 0)
        psmp = &string_match_params_default;
  again:while (p < pend) {
        register byte ch = *p;

        if (ch == psmp->any_substring) {
            pback = ++p, spback = sp;
            continue;
        } else if (ch == psmp->any_char) {
            if (sp == spend)
                return false;	/* str too short */
            p++, sp++;
            continue;
        } else if (ch == psmp->quote_next) {
            if (++p == pend)
                return true;	/* bad pattern */
            ch = *p;
        }
        if (sp == spend)
            return false;	/* str too short */
        if (*sp == ch ||
            (psmp->ignore_case && (*sp ^ ch) == 0x20 &&
             (ch &= ~0x20) >= 0x41 && ch <= 0x5a) ||
             (psmp->slash_equiv && ((ch == '\\' && *sp == '/') ||
             (ch == '/' && *sp == '\\')))
            )
            p++, sp++;
        else if (pback == 0)
            return false;	/* no * to back up to */
        else {
            sp = ++spback;
            p = pback;
        }
    }
    if (sp < spend) {		/* We got a match, but there are chars left over. */
        /* If we can back up, back up to the only place that */
        /* could produce a complete match, otherwise fail. */
        if (pback == 0)
            return false;
        p = pback;
        pback = 0;
        sp = spend - (pend - p);
        goto again;
    }
    return true;
}

/* ------ UID utilities ------ */

/* Compare two UIDs for equality. */
/* We know that at least one of them is valid. */
bool
uid_equal(register const gs_uid * puid1, register const gs_uid * puid2)
{
    if (puid1->id != puid2->id)
        return false;
    if (puid1->id >= 0)
        return true;		/* UniqueID */
    return
        !memcmp((const char *)puid1->xvalues,
                (const char *)puid2->xvalues,
                (uint) - (puid1->id) * sizeof(long));
}

/* Copy the XUID data for a uid, if needed, updating the uid in place. */
int
uid_copy(gs_uid *puid, gs_memory_t *mem, client_name_t cname)
{
    if (uid_is_XUID(puid)) {
        uint xsize = uid_XUID_size(puid);
        long *xvalues = (long *)
            gs_alloc_byte_array(mem, xsize, sizeof(long), cname);

        if (xvalues == 0)
            return_error(gs_error_VMerror);
        memcpy(xvalues, uid_XUID_values(puid), xsize * sizeof(long));
        puid->xvalues = xvalues;
    }
    return 0;
}

/* ------ Rectangle utilities ------ */

/*
 * Calculate the difference of two rectangles, a list of up to 4 rectangles.
 * Return the number of rectangles in the list, and set the first rectangle
 * to the intersection.
 */
int
int_rect_difference(gs_int_rect * outer, const gs_int_rect * inner,
                    gs_int_rect * diffs /*[4] */ )
{
    int x0 = outer->p.x, y0 = outer->p.y;
    int x1 = outer->q.x, y1 = outer->q.y;
    int count = 0;

    if (y0 < inner->p.y) {
        diffs[0].p.x = x0, diffs[0].p.y = y0;
        diffs[0].q.x = x1, diffs[0].q.y = min(y1, inner->p.y);
        outer->p.y = y0 = diffs[0].q.y;
        ++count;
    }
    if (y1 > inner->q.y) {
        diffs[count].p.x = x0, diffs[count].p.y = max(y0, inner->q.y);
        diffs[count].q.x = x1, diffs[count].q.y = y1;
        outer->q.y = y1 = diffs[count].p.y;
        ++count;
    }
    if (x0 < inner->p.x) {
        diffs[0].p.x = x0, diffs[0].p.y = y0;
        diffs[0].q.x = min(x1, inner->p.x), diffs[0].q.y = y1;
        outer->p.x = x0 = diffs[count].q.x;
        ++count;
    }
    if (x1 > inner->q.x) {
        diffs[count].p.x = max(x0, inner->q.x), diffs[count].p.y = y0;
        diffs[count].q.x = x1, diffs[count].q.y = y1;
        outer->q.x = x1 = diffs[count].p.x;
        ++count;
    }
    return count;
}