/* This is dvipdfmx, an eXtended version of dvipdfm by Mark A. Wicks.

   Copyright (C) 2002-2018 by Jin-Hwan Cho and Shunsaku Hirata,
   the dvipdfmx project team.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/

/*
 * References:
 *
 *  PostScript Language Reference Manual, 3rd. ed. (Adobe Systems Inc.)
 *    5.11.4 CMap Dictionaries
 *    5.11.5 FMapType 9 Composite Fonts
 *  Building CMap Files for CID-Keyed Fonts, Adobe Technical Note #5099
 *  CID-Keyed Font Technology Overview, Adobe Technical Note #5092
 *  Adobe CMap and CIDFont Files Specification, Adobe Technical Specification #5014
 *
 *  Undefined Character Handling:
 *    PLRM 3rd. ed., sec. 5.11.5., "Handling Undefined Characters"
 *
 * TODO:
 *   Only cid(range|char) allowed for CODE_TO_CID and bf(range|char) for CID_TO_CODE ?
 * 
 */

#include "dpx-cmap.h"

#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include "tectonic_bridge_core.h"
#include "dpx-cmap_p.h"
#include "dpx-dpxconf.h"
#include "dpx-dpxutil.h"
#include "dpx-error.h"
#include "dpx-mem.h"

static int __silent  = 0;

void
CMap_set_silent (int value)
{
    __silent = value ? 1 : 0;
}

/* Private funcs. */
static size_t  bytes_consumed   (CMap *cmap, const unsigned char *instr, size_t inbytes);
static void handle_undefined (CMap *cmap,
                              const unsigned char **inbuf, size_t *inbytesleft,
                              unsigned char **outbuf, size_t *outbytesleft);

static int  check_range      (CMap *cmap,
                              const unsigned char *srclo, const unsigned char *srchi, size_t srcdim,
                              const unsigned char *dst, size_t dstdim);

static unsigned char *get_mem (CMap *cmap, int size);
static mapDef *mapDef_new     (void);
static void    mapDef_release (mapDef *t);
static int     locate_tbl     (mapDef **cur, const unsigned char *code, int dim);

CMap *
CMap_new (void)
{
    CMap *cmap;

    cmap = NEW(1, struct CMap);
    cmap->name     = NULL;
    cmap->type     = CMAP_TYPE_CODE_TO_CID;
    cmap->wmode    = 0;
    cmap->useCMap  = NULL;
    cmap->CSI      = NULL;

    cmap->profile.minBytesIn  = 65535;
    cmap->profile.maxBytesIn  = 0;
    cmap->profile.minBytesOut = 65535;
    cmap->profile.maxBytesOut = 0;

    cmap->flags = 0;

    cmap->codespace.num    = 0;
    cmap->codespace.max    = 10;
    cmap->codespace.ranges = NEW(10, struct rangeDef);

    cmap->mapTbl  = NULL;

    cmap->mapData = NEW(1, struct mapData);
    cmap->mapData->prev = NULL;
    cmap->mapData->pos  = 0;
    cmap->mapData->data = NEW(MEM_ALLOC_SIZE, unsigned char);

    return cmap;
}

void
CMap_release (CMap *cmap)
{
    if (!cmap)
        return;

    free(cmap->name);
    if (cmap->CSI) {
        free(cmap->CSI->registry);
        free(cmap->CSI->ordering);
        free(cmap->CSI);
    }
    free(cmap->codespace.ranges);
    if (cmap->mapTbl)
        mapDef_release(cmap->mapTbl);
    {
        mapData *map = cmap->mapData;
        while (map != NULL) {
            mapData *prev = map->prev;
            free(map->data);
            free(map);
            map = prev;
        }
    }

    free(cmap);
}

bool
CMap_is_Identity (CMap *cmap)
{
    assert(cmap);

    return streq_ptr(cmap->name, "Identity-H")
           || streq_ptr(cmap->name, "Identity-V");
}

bool
CMap_is_valid (CMap *cmap)
{
    /* Quick check */
    if (!cmap || !(cmap->name) || cmap->type < CMAP_TYPE_IDENTITY ||
        cmap->type > CMAP_TYPE_CID_TO_CODE || cmap->codespace.num < 1 ||
        (cmap->type != CMAP_TYPE_IDENTITY && !cmap->mapTbl))
        return false;

    if (cmap->useCMap) {
        CIDSysInfo *csi1, *csi2;
        csi1 = CMap_get_CIDSysInfo(cmap);
        csi2 = CMap_get_CIDSysInfo(cmap->useCMap);
        if (strcmp(csi1->registry, csi2->registry) ||
            strcmp(csi1->ordering, csi2->ordering)) {
            dpx_warning("CIDSystemInfo mismatched %s <--> %s",
                 CMap_get_name(cmap), CMap_get_name(cmap->useCMap));
            return false;
        }
    }

    return true;
}

int
CMap_get_profile (CMap *cmap, int type)
{
    int value = 0;

    assert(cmap);
    switch (type) {
    case CMAP_PROF_TYPE_INBYTES_MIN:
        value = cmap->profile.minBytesIn;
        break;
    case CMAP_PROF_TYPE_INBYTES_MAX:
        value = cmap->profile.maxBytesIn;
        break;
    case CMAP_PROF_TYPE_OUTBYTES_MIN:
        value = cmap->profile.maxBytesOut;
        break;
    case CMAP_PROF_TYPE_OUTBYTES_MAX:
        value = cmap->profile.maxBytesOut;
        break;
    default:
        _tt_abort("%s: Unrecognized profile type %d.", CMAP_DEBUG_STR, type);
    }

    return value;
}

/*
 * Put notdef chars for codes not declared in notdef(range|char)
 */
static void
handle_undefined (CMap *cmap,
                  const unsigned char **inbuf, size_t *inbytesleft,
                  unsigned char **outbuf, size_t *outbytesleft)
{
    size_t len = 0;

    if (*outbytesleft < 2)
        _tt_abort("%s: Buffer overflow.", CMAP_DEBUG_STR);

    switch (cmap->type) {
    case CMAP_TYPE_CODE_TO_CID:
        memcpy(*outbuf, CID_NOTDEF_CHAR, 2);
        break;
    case CMAP_TYPE_TO_UNICODE:
        memcpy(*outbuf, UCS_NOTDEF_CHAR, 2);
        break;
    default:
        dpx_warning("Cannot handle undefined mapping for this type of CMap mapping: %d", cmap->type);
        dpx_warning("<0000> is used for .notdef char.");
        memset(*outbuf, 0, 2);
    }
    *outbuf += 2;
    *outbytesleft -= 2;

    len = bytes_consumed(cmap, *inbuf, *inbytesleft);

    *inbuf  += len;
    *inbytesleft  -= len;
}

void
CMap_decode_char (CMap *cmap,
                  const unsigned char **inbuf, size_t *inbytesleft,
                  unsigned char **outbuf, size_t *outbytesleft)
{
    mapDef *t;
    const unsigned char *p, *save;
    unsigned char c = 0;
    size_t     count = 0;

    p = save = *inbuf;
    /*
     * First handle some special cases:
     */
    if (cmap->type == CMAP_TYPE_IDENTITY) {
        if ((*inbytesleft) % 2)
            _tt_abort("%s: Invalid/truncated input string.", CMAP_DEBUG_STR);
        if (*outbytesleft < 2)
            _tt_abort("%s: Buffer overflow.", CMAP_DEBUG_STR);
        memcpy(*outbuf, *inbuf, 2);
        *inbuf  += 2;
        *outbuf += 2;
        *outbytesleft -= 2;
        *inbytesleft  -= 2;
        return;
    } else if (!cmap->mapTbl) {
        if (cmap->useCMap) {
            CMap_decode_char(cmap->useCMap, inbuf, inbytesleft, outbuf, outbytesleft);
            return;
        } else {
            /* no mapping available in this CMap */
            dpx_warning("No mapping available for this character.");
            handle_undefined(cmap, inbuf, inbytesleft, outbuf, outbytesleft);
            return;
        }
    }

    assert(cmap->mapTbl);
    t = cmap->mapTbl;
    while (count < *inbytesleft) {
        c = *p++;
        count++;
        if (LOOKUP_END(t[c].flag))
            break;
        t = t[c].next;
    }
    if (LOOKUP_CONTINUE(t[c].flag)) /* need more bytes */
        _tt_abort("%s: Premature end of input string.", CMAP_DEBUG_STR);
    else if (!MAP_DEFINED(t[c].flag)) {
        if (cmap->useCMap) {
            CMap_decode_char(cmap->useCMap, inbuf, inbytesleft, outbuf, outbytesleft);
            return;
        } else {
            /* no mapping available in this CMap */
            dpx_warning("No character mapping available.");
            dpx_message(" CMap name: %s\n", CMap_get_name(cmap));
            dpx_message(" input str: ");
            dpx_message("<");
            while (save < p) {
                dpx_message("%02x", *save);
                save++;
            }
            dpx_message(">\n");
            /*
             * We know partial match found up to `count' bytes,
             * but we will not use this information for the sake of simplicity.
             */
            handle_undefined(cmap, inbuf, inbytesleft, outbuf, outbytesleft);
            return;
        }
    } else {
        switch (MAP_TYPE(t[c].flag)) {
        case MAP_IS_NOTDEF:
            dpx_warning("Character mapped to .notdef found.");
            /* continue */
        case MAP_IS_CID: case MAP_IS_CODE:
            if (*outbytesleft >= t[c].len)
                memcpy(*outbuf, t[c].code, t[c].len);
            else
                _tt_abort("%s: Buffer overflow.", CMAP_DEBUG_STR);
            *outbuf       += t[c].len;
            *outbytesleft -= t[c].len;
            break;
        case MAP_IS_NAME:
            _tt_abort("%s: CharName mapping not supported.", CMAP_DEBUG_STR);
            break;
        default:
            _tt_abort("%s: Unknown mapping type.", CMAP_DEBUG_STR);
        }
        if (inbytesleft)
            *inbytesleft -= count;
        *inbuf = p;
    }
}

/*
 * For convenience, it does not do decoding to CIDs.
 */
size_t
CMap_decode (CMap *cmap,
             const unsigned char **inbuf,  size_t *inbytesleft,
             unsigned char **outbuf, size_t *outbytesleft)
{
    size_t count;

    assert(cmap && inbuf && outbuf);
    assert(inbytesleft && outbytesleft);
    for (count = 0;*inbytesleft > 0 && *outbytesleft > 0; count++)
        CMap_decode_char(cmap, inbuf, inbytesleft, outbuf, outbytesleft);

    return count;
}

char *
CMap_get_name (CMap *cmap)
{
    assert(cmap);
    return cmap->name;
}

int
CMap_get_type (CMap *cmap)
{
    assert(cmap);
    return cmap->type;
}

int
CMap_get_wmode (CMap *cmap)
{
    assert(cmap);
    return cmap->wmode;
}

CIDSysInfo *
CMap_get_CIDSysInfo (CMap *cmap)
{
    assert(cmap);
    return cmap->CSI;
}

void
CMap_set_name (CMap *cmap, const char *name)
{
    assert(cmap);
    free(cmap->name);
    cmap->name = NEW(strlen(name)+1, char);
    strcpy(cmap->name, name);
}

void
CMap_set_type (CMap *cmap, int type)
{
    assert(cmap);
    cmap->type = type;
}

void
CMap_set_wmode (CMap *cmap, int wmode)
{
    assert(cmap);
    cmap->wmode = wmode;
}

void
CMap_set_CIDSysInfo (CMap *cmap, const CIDSysInfo *csi)
{
    assert(cmap);

    if (cmap->CSI) {
        free(cmap->CSI->registry);
        free(cmap->CSI->ordering);
        free(cmap->CSI);
    }

    if (csi && csi->registry && csi->ordering) {
        cmap->CSI = NEW(1, CIDSysInfo);
        cmap->CSI->registry = NEW(strlen(csi->registry)+1, char);
        strcpy(cmap->CSI->registry, csi->registry);
        cmap->CSI->ordering = NEW(strlen(csi->ordering)+1, char);
        strcpy(cmap->CSI->ordering, csi->ordering);
        cmap->CSI->supplement = csi->supplement;
    } else {
        dpx_warning("Invalid CIDSystemInfo.");
        cmap->CSI = NULL;
    }
}

/*
 * Can have muliple entry ?
 */
void
CMap_set_usecmap (CMap *cmap, CMap *ucmap)
{
    unsigned int i;

    assert(cmap);
    assert(ucmap); /* Maybe if (!ucmap) _tt_abort() is better for this. */

    if (cmap == ucmap)
        _tt_abort("%s: Identical CMap object cannot be used for usecmap CMap: 0x%p=0x%p",
              CMAP_DEBUG_STR, cmap, ucmap);

    /* Check if ucmap have neccesary information. */
    if (!CMap_is_valid(ucmap))
        _tt_abort("%s: Invalid CMap.", CMAP_DEBUG_STR);

    /*
     *  CMapName of cmap can be undefined when usecmap is executed in CMap parsing.
     *  And it is also possible CSI is not defined at that time.
     */
    if (streq_ptr(cmap->name, ucmap->name))
        _tt_abort("%s: CMap refering itself not allowed: CMap %s --> %s",
              CMAP_DEBUG_STR, cmap->name, ucmap->name);

    if (cmap->CSI && cmap->CSI->registry && cmap->CSI->ordering) {
        if (strcmp(cmap->CSI->registry, ucmap->CSI->registry) ||
            strcmp(cmap->CSI->ordering, ucmap->CSI->ordering))
            _tt_abort("%s: CMap %s required by %s have different CSI.",
                  CMAP_DEBUG_STR, CMap_get_name(cmap), CMap_get_name(ucmap));
    }

    /* We must copy codespaceranges. */
    for (i = 0; i < ucmap->codespace.num; i++) {
        rangeDef *csr = ucmap->codespace.ranges + i;
        CMap_add_codespacerange(cmap, csr->codeLo, csr->codeHi, csr->dim);
    }

    cmap->useCMap = ucmap;
}

/* Test the validity of character c. */
static int
CMap_match_codespace (CMap *cmap, const unsigned char *c, size_t dim)
{
    unsigned int i, pos;

    assert(cmap);
    for (i = 0; i < cmap->codespace.num; i++) {
        rangeDef *csr = cmap->codespace.ranges + i;
        if (csr->dim != dim)
            continue;
        for (pos = 0; pos < dim; pos++) {
            if (c[pos] > csr->codeHi[pos] || c[pos] < csr->codeLo[pos])
                break;
        }
        if (pos == dim)
            return 0; /* Valid */
    }

    return -1; /* Invalid */
}

/*
 * No overlapping codespace ranges are allowed, otherwise mapping is ambiguous.
 */
int
CMap_add_codespacerange (CMap *cmap,
                         const unsigned char *codelo, const unsigned char *codehi, size_t dim)
{
    rangeDef *csr = NULL;
    unsigned int i;

    assert(cmap && dim > 0);

    for (i = 0; i < cmap->codespace.num; i++) {
        size_t j;
        bool overlap = true;
        csr = cmap->codespace.ranges + i;
        for (j = 0; j < MIN(csr->dim, dim) && overlap; j++) {
            if ((codelo[j] >= csr->codeLo[j] && codelo[j] <= csr->codeHi[j]) ||
                (codehi[j] >= csr->codeLo[j] && codehi[j] <= csr->codeHi[j]))
                overlap = true;
            else
                overlap = false;
        }
        if (overlap) {
            dpx_warning("Overlapping codespace found. (ingored)");
            return -1;
        }
    }

    if (dim < cmap->profile.minBytesIn)
        cmap->profile.minBytesIn = dim;
    if (dim > cmap->profile.maxBytesIn)
        cmap->profile.maxBytesIn = dim;

    if (cmap->codespace.num + 1 > cmap->codespace.max) {
        cmap->codespace.max += 10;
        cmap->codespace.ranges = RENEW(cmap->codespace.ranges, cmap->codespace.max, struct rangeDef);
    }

    csr = cmap->codespace.ranges + cmap->codespace.num;
    csr->dim    = dim;
    csr->codeHi = get_mem(cmap, dim);
    csr->codeLo = get_mem(cmap, dim);
    memcpy(csr->codeHi, codehi, dim);
    memcpy(csr->codeLo, codelo, dim);

    (cmap->codespace.num)++;

    return 0;
}

int
CMap_add_notdefchar (CMap *cmap, const unsigned char *src, size_t srcdim, CID dst)
{
    return CMap_add_notdefrange(cmap, src, src, srcdim, dst);
}

int
CMap_add_notdefrange (CMap *cmap,
                      const unsigned char *srclo, const unsigned char *srchi, size_t srcdim, CID dst)
{
    int     c;
    mapDef *cur;

    assert(cmap);
    /* dst not used here */
    /* FIXME */
    if (check_range(cmap, srclo, srchi, srcdim, (const unsigned char *)&dst, 2) < 0)
        return -1;

    if (cmap->mapTbl == NULL )
        cmap->mapTbl = mapDef_new();

    cur = cmap->mapTbl;
    if (locate_tbl(&cur, srclo, srcdim) < 0)
        return -1;

    for (c = srclo[srcdim-1]; c <= srchi[srcdim-1]; c++) {
        if (MAP_DEFINED(cur[c].flag)) {
            if (!__silent)
                dpx_warning("Trying to redefine already defined code mapping. (ignored)");
        } else {
            cur[c].flag = (MAP_LOOKUP_END|MAP_IS_NOTDEF);
            cur[c].code = get_mem(cmap, 2);
            cur[c].len  = 2;
            cur[c].code[0] = dst >> 8;
            cur[c].code[1] = dst & 0xff;
        }
        /* Do not do dst++ for notdefrange  */
    }

    return 0;
}

int
CMap_add_bfchar (CMap *cmap,
                 const unsigned char *src, size_t srcdim,
                 const unsigned char *dst, size_t dstdim)
{
    return CMap_add_bfrange(cmap, src, src, srcdim, dst, dstdim);
}

int
CMap_add_bfrange (CMap *cmap,
                  const unsigned char *srclo, const unsigned char *srchi, size_t srcdim,
                  const unsigned char *base, size_t dstdim)
{
    int     c, last_byte, i;
    mapDef *cur;

    assert(cmap);
    if (check_range(cmap, srclo, srchi, srcdim, base, dstdim) < 0)
        return -1;

    if (cmap->mapTbl == NULL)
        cmap->mapTbl = mapDef_new();

    cur = cmap->mapTbl;
    if (locate_tbl(&cur, srclo, srcdim) < 0)
        return -1;

    for (c = srclo[srcdim-1]; c <= srchi[srcdim-1]; c++) {
        /* According to 5014.CIDFont_Spec.pdf (p.52),
         * Code mappings (unlike codespace ranges) may overlap,
         * but succeeding maps superceded preceding maps.
         * (reported and patched by Luo Jie on 2007/12/2)
         */
        if (!MAP_DEFINED(cur[c].flag) || cur[c].len < dstdim) {
            cur[c].flag = (MAP_LOOKUP_END|MAP_IS_CODE);
            cur[c].code = get_mem(cmap, dstdim);
        }
        /*
         * We assume restriction to code ranges also applied here.
         * Addition <00FF> + 1 is undefined.
         *
         * Changed on 2004-03-20:
         *
         *  Should be treated as <0100> in Acrobat's "ToUnicode" CMap.
         */
        cur[c].len = dstdim;
        memcpy(cur[c].code, base, dstdim);

        last_byte = c - srclo[srcdim-1] + base[dstdim-1];
        cur[c].code[dstdim-1] = (last_byte & 0xFF);
        for (i = dstdim - 2; i >= 0 && last_byte > 255; i--) {
            last_byte = cur[c].code[i] + 1;
            cur[c].code[i] = (last_byte & 0xFF);
        }
    }

    return 0;
}

int
CMap_add_cidchar (CMap *cmap, const unsigned char *src, size_t srcdim, CID dst)
{
    return CMap_add_cidrange(cmap, src, src, srcdim, dst);
}

int
CMap_add_cidrange (CMap *cmap,
                   const unsigned char *srclo, const unsigned char *srchi, size_t srcdim, CID base)
{
    size_t i, c, v;
    mapDef *cur;

    assert(cmap);
    /* base not used here */
    if (check_range(cmap, srclo, srchi, srcdim, (const unsigned char *)&base, 2) < 0) /* FIXME */
        return -1;

    if (cmap->mapTbl == NULL )
        cmap->mapTbl = mapDef_new();

    cur = cmap->mapTbl;
    if (locate_tbl(&cur, srclo, srcdim) < 0)
        return -1;

    for (v = 0, i = 0; i < srcdim - 1; i++)
        v = (v << 8) + srclo[i];

    for (c = srclo[srcdim-1]; c <= srchi[srcdim-1]; c++) {
        if (cur[c].flag != 0) {
            if (!__silent)
                dpx_warning("Trying to redefine already defined CID mapping. (ignored)");
        } else {
            cur[c].flag = (MAP_LOOKUP_END|MAP_IS_CID);
            cur[c].len  = 2;
            cur[c].code = get_mem(cmap, 2);
            cur[c].code[0] = base >> 8;
            cur[c].code[1] = base & 0xff;
        }
        if (base >= CID_MAX)
            dpx_warning("CID number too large.");
        base++;
    }

    return 0;
}

static void
mapDef_release (mapDef *t)
{
    int c;

    assert(t);
    for (c = 0; c < 256; c++) {
        if (LOOKUP_CONTINUE(t[c].flag))
            mapDef_release(t[c].next);
    }
    free(t);
}

static mapDef *
mapDef_new (void)
{
    mapDef *t;
    int     c;

    t = NEW(256, mapDef);
    for (c=0; c<256; c++) {
        t[c].flag = (MAP_LOOKUP_END|MAP_IS_UNDEF);
        t[c].code = NULL;
        t[c].next = NULL;
    }

    return t;
}

static unsigned char *
get_mem (CMap *cmap, int size)
{
    mapData *map;
    unsigned char  *p;

    assert(cmap && cmap->mapData && size >= 0);
    map = cmap->mapData;
    if (map->pos + size >= MEM_ALLOC_SIZE) {
        mapData *prev = map;
        map = NEW(1, struct mapData);
        map->data = NEW(MEM_ALLOC_SIZE, unsigned char);
        map->prev = prev;
        map->pos  = 0;
        cmap->mapData = map;
    }
    p = map->data + map->pos;
    map->pos += size;

    return p;
}

static int
locate_tbl (mapDef **cur, const unsigned char *code, int dim)
{
    int i, c;

    assert(cur && *cur);
    for (i = 0; i < dim-1; i++) {
        c = code[i];
        if (MAP_DEFINED((*cur)[c].flag)) {
            dpx_warning("Ambiguous CMap entry.");
            return -1;
        }
        if ((*cur)[c].next == NULL)  /* create new node */
            (*cur)[c].next = mapDef_new();
        (*cur)[c].flag  |= MAP_LOOKUP_CONTINUE;
        *cur = (*cur)[c].next;
    }

    return 0;
}

/*
 * Guess how many bytes consumed as a `single' character:
 * Substring of length bytesconsumed bytes of input string is interpreted as
 * a `single' character by CMap_decode().
 */
static size_t
bytes_consumed (CMap *cmap, const unsigned char *instr, size_t inbytes)
{
    size_t i, pos, longest = 0, bytesconsumed;

    assert(cmap);
    for (i = 0; i < cmap->codespace.num; i++) {
        rangeDef *csr = cmap->codespace.ranges + i;
        for (pos = 0; pos < MIN(csr->dim, inbytes); pos++) {
            if (instr[pos] > csr->codeHi[pos] || instr[pos] < csr->codeLo[pos])
                break;
        }
        if (pos == csr->dim) /* part of instr is totally valid in this codespace. */
            return csr->dim;
        if (pos > longest)
            longest = pos;
    }

    if (i == cmap->codespace.num) /* No matching at all */
        bytesconsumed = cmap->profile.minBytesIn;
    else {
        bytesconsumed = cmap->profile.maxBytesIn;
        for (i = 0; i< cmap->codespace.num; i++) {
            rangeDef *csr = cmap->codespace.ranges + i;
            if (csr->dim > longest && csr->dim < bytesconsumed)
                bytesconsumed = csr->dim;
        }
    }

    return bytesconsumed;
}

static int
check_range (CMap *cmap,
             const unsigned char *srclo, const unsigned char *srchi, size_t srcdim,
             const unsigned char *dst, size_t dstdim)
{
    if ((srcdim < 1 || dstdim < 1) ||
        (!srclo || !srchi || !dst) ||
        memcmp(srclo, srchi, srcdim - 1) ||
        srclo[srcdim-1] > srchi[srcdim-1]) {
        dpx_warning("Invalid CMap mapping entry. (ignored)");
        return -1;
    }

    if (CMap_match_codespace(cmap, srclo, srcdim) < 0 ||
        CMap_match_codespace(cmap, srchi, srcdim) < 0) {
        dpx_warning("Invalid CMap mapping entry. (ignored)");
        return -1;
    }

    if (srcdim < cmap->profile.minBytesIn)
        cmap->profile.minBytesIn  = srcdim;
    if (srcdim > cmap->profile.maxBytesIn)
        cmap->profile.maxBytesIn  = srcdim;
    if (dstdim < cmap->profile.minBytesOut)
        cmap->profile.minBytesOut = dstdim;
    if (dstdim > cmap->profile.maxBytesOut)
        cmap->profile.maxBytesOut = dstdim;

    return 0;
}

/************************** CMAP_CACHE **************************/
#include "dpx-cmap_read.h"

#define CMAP_CACHE_ALLOC_SIZE 16u

struct CMap_cache {
    int    num;
    int    max;
    CMap **cmaps;
};

static struct CMap_cache *__cache = NULL;

#define CHECK_ID(n) do {                                                \
        if (! __cache)                                                  \
            _tt_abort("%s: CMap cache not initialized.", CMAP_DEBUG_STR);   \
        if ((n) < 0 || (n) >= __cache->num)                             \
            _tt_abort("Invalid CMap ID %d", (n));                           \
    } while (0)

void
CMap_cache_init (void)
{
    static unsigned char range_min[2] = {0x00, 0x00};
    static unsigned char range_max[2] = {0xff, 0xff};

    if (__cache)
        _tt_abort("%s: Already initialized.", CMAP_DEBUG_STR);

    __cache = NEW(1, struct CMap_cache);

    __cache->max   = CMAP_CACHE_ALLOC_SIZE;
    __cache->cmaps = NEW(__cache->max, CMap *);
    __cache->num   = 0;

    /* Create Identity mapping */
    __cache->cmaps[0] = CMap_new();
    CMap_set_name (__cache->cmaps[0], "Identity-H");
    CMap_set_type (__cache->cmaps[0], CMAP_TYPE_IDENTITY);
    CMap_set_wmode(__cache->cmaps[0], 0);
    CMap_set_CIDSysInfo(__cache->cmaps[0], &CSI_IDENTITY);
    CMap_add_codespacerange(__cache->cmaps[0], range_min, range_max, 2);

    __cache->cmaps[1] = CMap_new();
    CMap_set_name (__cache->cmaps[1], "Identity-V");
    CMap_set_type (__cache->cmaps[1], CMAP_TYPE_IDENTITY);
    CMap_set_wmode(__cache->cmaps[1], 1);
    CMap_set_CIDSysInfo(__cache->cmaps[1], &CSI_IDENTITY);
    CMap_add_codespacerange(__cache->cmaps[1], range_min, range_max, 2);

    __cache->num += 2;
}

CMap *
CMap_cache_get (int id)
{
    CHECK_ID(id);
    return __cache->cmaps[id];
}


int
CMap_cache_find (const char *cmap_name)
{
    int id = 0;
    rust_input_handle_t handle = NULL;

    if (!__cache)
        CMap_cache_init();

    assert(__cache);

    for (id = 0; id < __cache->num; id++) {
        char *name = NULL;
        /* CMapName may be undefined when processing usecmap. */
        name = CMap_get_name(__cache->cmaps[id]);
        if (name && streq_ptr(cmap_name, name))
            return id;
    }

    handle = ttstub_input_open(cmap_name, TTBC_FILE_FORMAT_CMAP, 0);
    if (handle == NULL)
        return -1;

    if (CMap_parse_check_sig(handle) < 0) {
        ttstub_input_close(handle);
        return -1;
    }

    if (dpx_conf.verbose_level > 0)
        dpx_message("(CMap:%s", cmap_name);

    if (__cache->num >= __cache->max) {
        __cache->max   += CMAP_CACHE_ALLOC_SIZE;
        __cache->cmaps = RENEW(__cache->cmaps, __cache->max, CMap *);
    }

    id = __cache->num;
    __cache->num++;
    __cache->cmaps[id] = CMap_new();

    if (CMap_parse(__cache->cmaps[id], handle) < 0)
        _tt_abort("%s: Parsing CMap file failed.", CMAP_DEBUG_STR);

    ttstub_input_close(handle);

    if (dpx_conf.verbose_level > 0)
        dpx_message(")");

    return id;
}

int
CMap_cache_add (CMap *cmap)
{
    int   id;
    char *cmap_name0, *cmap_name1;

    if (!CMap_is_valid(cmap))
        _tt_abort("%s: Invalid CMap.", CMAP_DEBUG_STR);

    for (id = 0; id < __cache->num; id++) {
        cmap_name0 = CMap_get_name(cmap);
        cmap_name1 = CMap_get_name(__cache->cmaps[id]);
        if (streq_ptr(cmap_name0, cmap_name1)) {
            _tt_abort("%s: CMap \"%s\" already defined.",
                  CMAP_DEBUG_STR, cmap_name0);
        }
    }

    if (__cache->num >= __cache->max) {
        __cache->max   += CMAP_CACHE_ALLOC_SIZE;
        __cache->cmaps = RENEW(__cache->cmaps, __cache->max, CMap *);
    }
    id = __cache->num;
    (__cache->num)++;
    __cache->cmaps[id] = cmap;

    return id;
}

void
CMap_cache_close (void)
{
    if (__cache) {
        int id;
        for (id = 0; id < __cache->num; id++) {
            CMap_release(__cache->cmaps[id]);
        }
        free(__cache->cmaps);
        __cache = mfree(__cache);
    }
}