path: root/gs/base/gsicc_cache.c

/* Copyright (C) 2001-2012 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.,  7 Mt. Lassen Drive - Suite A-134, San Rafael,
   CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/*  GS ICC link cache.  Initial stubbing of functions.  */

#include "std.h"
#include "stdpre.h"
#include "gstypes.h"
#include "gsmemory.h"
#include "gsstruct.h"
#include "scommon.h"
#include "gx.h"
#include "gxistate.h"
#include "smd5.h"
#include "gscms.h"
#include "gsicc_cms.h"
#include "gsicc_manage.h"
#include "gsicc_cache.h"
#include "gserrors.h"
#include "gsmalloc.h" /* Needed for named color structure allocation */
#include "string_.h"  /* Needed for named color structure allocation */
#include "gxsync.h"
#include "gzstate.h"
        /*
         *  Note that the the external memory used to maintain
         *  links in the CMS is generally not visible to GS.
         *  For most CMS's the  links are 33x33x33x33x4 bytes at worst
         *  for a CMYK to CMYK MLUT which is about 4.5Mb per link.
         *  If the link were matrix based it would be much much smaller.
         *  We will likely want to do at least have an estimate of the
         *  memory used based upon how the CMS is configured.
         *  This will be done later.  For now, just limit the number
         *  of links.
         */
#define ICC_CACHE_MAXLINKS 50

/* Static prototypes */

static gsicc_link_t * gsicc_alloc_link(gs_memory_t *memory, gsicc_hashlink_t hashcode);

static void gsicc_get_cspace_hash(gsicc_manager_t *icc_manager, gx_device *dev,
                                  cmm_profile_t *profile, int64_t *hash);

static void gsicc_compute_linkhash(gsicc_manager_t *icc_manager, gx_device *dev,
                                   cmm_profile_t *input_profile,
                                   cmm_profile_t *output_profile,
                                   gsicc_rendering_param_t *rendering_params,
                                   gsicc_hashlink_t *hash);

static gsicc_link_t* gsicc_find_zeroref_cache(gsicc_link_cache_t *icc_link_cache);

static void gsicc_remove_link(gsicc_link_t *link, gs_memory_t *memory);

static void gsicc_get_buff_hash(unsigned char *data, int64_t *hash, unsigned int num_bytes);

static void rc_gsicc_link_cache_free(gs_memory_t * mem, void *ptr_in, client_name_t cname);

/* Structure pointer information */

struct_proc_finalize(icc_link_finalize);

gs_private_st_ptrs3_final(st_icc_link, gsicc_link_t, "gsiccmanage_link",
                    icc_link_enum_ptrs, icc_link_reloc_ptrs, icc_link_finalize,
                    icc_link_cache, next, wait);

struct_proc_finalize(icc_linkcache_finalize);

gs_private_st_ptrs3_final(st_icc_linkcache, gsicc_link_cache_t, "gsiccmanage_linkcache",
                    icc_linkcache_enum_ptrs, icc_linkcache_reloc_ptrs, icc_linkcache_finalize,
                    head, lock, wait);

/* These are used to construct a hash for the ICC link based upon the
   render parameters */

#define BP_SHIFT 0
#define REND_SHIFT 8
#define PRESERVE_SHIFT 16

/**
 * gsicc_cache_new: Allocate a new ICC cache manager
 * Return value: Pointer to allocated manager, or NULL on failure.
 **/

gsicc_link_cache_t *
gsicc_cache_new(gs_memory_t *memory)
{
    gsicc_link_cache_t *result;

    /* We want this to be maintained in stable_memory.  It should be be effected by the
       save and restores */
    result = gs_alloc_struct(memory->stable_memory, gsicc_link_cache_t, &st_icc_linkcache,
                             "gsicc_cache_new");
    if ( result == NULL )
        return(NULL);
    result->lock = gx_monitor_alloc(memory->stable_memory);
    result->wait = gx_semaphore_alloc(memory->stable_memory);
    if (result->lock == NULL || result->wait == NULL) {
        gs_free_object(memory->stable_memory, result, "gsicc_cache_new");
        return(NULL);
    }
    result->num_waiting = 0;
    rc_init_free(result, memory->stable_memory, 1, rc_gsicc_link_cache_free);
    result->head = NULL;
    result->num_links = 0;
    result->memory = memory->stable_memory;
    if_debug2m(gs_debug_flag_icc, memory,
               "[icc] Allocating link cache = 0x%x memory = 0x%x\n", result,
               result->memory);
    return(result);
}

static void
rc_gsicc_link_cache_free(gs_memory_t * mem, void *ptr_in, client_name_t cname)
{
    /* Ending the entire cache.  The ref counts on all the links should be 0 */
    gsicc_link_cache_t *link_cache = (gsicc_link_cache_t * ) ptr_in;

    if_debug2m(gs_debug_flag_icc, mem,
               "[icc] Removing link cache = 0x%x memory = 0x%x\n",
               link_cache, link_cache->memory);
    gs_free_object(mem->stable_memory, link_cache, "rc_gsicc_link_cache_free");
}

/* release the semaphore and monitor of the link_cache when it is freed */
void
icc_linkcache_finalize(const gs_memory_t *mem, void *ptr)
{
    gsicc_link_cache_t *link_cache = (gsicc_link_cache_t * ) ptr;

    while (link_cache->head != NULL) {
        gsicc_remove_link(link_cache->head, mem);
        link_cache->num_links--;
    }
#ifdef DEBUG
    if (link_cache->num_links != 0) {
        emprintf1(mem, "num_links is %d, should be 0.\n", link_cache->num_links);
    }
#endif
    gx_semaphore_free(link_cache->wait);
    link_cache->wait = NULL;
    gx_monitor_free(link_cache->lock);
    link_cache->lock = NULL;
}

static gsicc_link_t *
gsicc_alloc_link(gs_memory_t *memory, gsicc_hashlink_t hashcode)
{
    gsicc_link_t *result;

    /* The link has to be added in stable memory. We want them
       to be maintained across the gsave and grestore process */
    result = gs_alloc_struct(memory->stable_memory, gsicc_link_t, &st_icc_link,
                             "gsicc_alloc_link");
    if (result == NULL)
        return NULL;
    result->wait = gx_semaphore_alloc(memory->stable_memory);
    if (result->wait == NULL) {
        gs_free_object(memory->stable_memory, result, "gsicc_alloc_link(wait)");
        return NULL;
    }
    /* set up placeholder values */
    result->is_monitored = false;
    result->orig_procs.map_buffer = NULL;
    result->orig_procs.map_color = NULL;
    result->orig_procs.free_link = NULL;
    result->next = NULL;
    result->link_handle = NULL;
    result->procs.map_buffer = gscms_transform_color_buffer;
    result->procs.map_color = gscms_transform_color;
    result->procs.free_link = gscms_release_link;
    result->hashcode.link_hashcode = hashcode.link_hashcode;
    result->hashcode.des_hash = 0;
    result->hashcode.src_hash = 0;
    result->hashcode.rend_hash = 0;
    result->ref_count = 1;		/* prevent it from being freed */
    result->includes_softproof = 0;
    result->includes_devlink = 0;
    result->is_identity = false;
    result->valid = false;		/* not yet complete */
    result->num_waiting = 0;
    return(result);
}

static void
gsicc_set_link_data(gsicc_link_t *icc_link, void *link_handle,
                    gsicc_hashlink_t hashcode, gx_monitor_t *lock,
                    bool includes_softproof, bool includes_devlink,
                    bool pageneutralcolor, gsicc_colorbuffer_t data_cs)
{
    gx_monitor_enter(lock);		/* lock the cache while changing data */
    icc_link->link_handle = link_handle;
    gscms_get_link_dim(link_handle, &(icc_link->num_input), &(icc_link->num_output));
    icc_link->hashcode.link_hashcode = hashcode.link_hashcode;
    icc_link->hashcode.des_hash = hashcode.des_hash;
    icc_link->hashcode.src_hash = hashcode.src_hash;
    icc_link->hashcode.rend_hash = hashcode.rend_hash;
    icc_link->includes_softproof = includes_softproof;
    icc_link->includes_devlink = includes_devlink;
    if ( (hashcode.src_hash == hashcode.des_hash) &&
          !includes_softproof && !includes_devlink) {
        icc_link->is_identity = true;
    } else {
        icc_link->is_identity = false;
    }
    icc_link->valid = true;

    /* Set up for monitoring */
    icc_link->data_cs = data_cs;
    if (pageneutralcolor) 
        gsicc_mcm_set_link(icc_link);

    /* Now release any tasks/threads waiting for these contents */
    while (icc_link->num_waiting > 0) {
        gx_semaphore_signal(icc_link->wait);
        icc_link->num_waiting--;
    }
    gx_monitor_leave(lock);	/* done with updating, let everyone run */
}

static void
gsicc_link_free_contents(gsicc_link_t *icc_link)
{
    icc_link->procs.free_link(icc_link);
    gx_semaphore_free(icc_link->wait);
    icc_link->wait = NULL;
}

void
gsicc_link_free(gsicc_link_t *icc_link, gs_memory_t *memory)
{
    gsicc_link_free_contents(icc_link);

    gs_free_object(memory->stable_memory, icc_link, "gsicc_link_free");
}

/* release the semaphore of the link when it is freed */
void
icc_link_finalize(const gs_memory_t *mem, void *ptr)
{
    gsicc_link_t *icc_link = (gsicc_link_t * ) ptr;

    gsicc_link_free_contents(icc_link);
}

static void
gsicc_mash_hash(gsicc_hashlink_t *hash)
{
    hash->link_hashcode =
        (hash->des_hash >> 1) ^ (hash->rend_hash) ^ (hash->src_hash);
}

int64_t 
gsicc_get_hash(cmm_profile_t *profile)
{
    if (!profile->hash_is_valid) {
        int64_t hash;

        gsicc_get_icc_buff_hash(profile->buffer, &hash, profile->buffer_size);
        profile->hashcode = hash;
        profile->hash_is_valid = true;
    }
    return profile->hashcode;
}

void
gsicc_get_icc_buff_hash(unsigned char *buffer, int64_t *hash, unsigned int buff_size)
{
    gsicc_get_buff_hash(buffer, hash, buff_size);
}

static void
gsicc_get_buff_hash(unsigned char *data, int64_t *hash, unsigned int num_bytes)
{
    gs_md5_state_t md5;
    byte digest[16];
    int k;
    int64_t word1,word2,shift;

   /* We could probably do something faster than this. But use this for now. */
    gs_md5_init(&md5);
    gs_md5_append(&md5, data, num_bytes);
    gs_md5_finish(&md5, digest);

    /* For now, xor this into 64 bit word */
    word1 = 0;
    word2 = 0;
    shift = 0;

    /* need to do it this way because of
       potential word boundary issues */
    for( k = 0; k<8; k++) {
       word1 += ((int64_t) digest[k]) << shift;
       word2 += ((int64_t) digest[k+8]) << shift;
       shift += 8;
    }
    *hash = word1 ^ word2;
}

/* Compute a hash code for the current transformation case.
    This just computes a 64bit xor of upper and lower portions of
    md5 for the input, output
    and rendering params structure.  We may change this later */
static void
gsicc_compute_linkhash(gsicc_manager_t *icc_manager, gx_device *dev,
                       cmm_profile_t *input_profile,
                       cmm_profile_t *output_profile,
                       gsicc_rendering_param_t *rendering_params,
                       gsicc_hashlink_t *hash)
{
   /* first get the hash codes for the color spaces */
    gsicc_get_cspace_hash(icc_manager, dev, input_profile, &(hash->src_hash));
    gsicc_get_cspace_hash(icc_manager, dev, output_profile, &(hash->des_hash));

    /* now for the rendering paramaters, just use the word itself.  At this
       point in time, we only include the black point setting, the intent
       and if we are preserving black.  We don't differentiate at this time
       with object type since the current CMM does not create different
       links based upon this type setting.  Other parameters such as cmm
       and override ICC are used prior to a link creation and so should also
       not factor into the link hash calculation */
    hash->rend_hash = ((rendering_params->black_point_comp) << BP_SHIFT) +
                      ((rendering_params->rendering_intent) << REND_SHIFT) +
                      ((rendering_params->preserve_black) << PRESERVE_SHIFT);
   /* for now, mash all of these into a link hash */
   gsicc_mash_hash(hash);
}

static void
gsicc_get_cspace_hash(gsicc_manager_t *icc_manager, gx_device *dev,
                      cmm_profile_t *cmm_icc_profile_data, int64_t *hash)
{
    cmm_dev_profile_t *dev_profile;
    cmm_profile_t *icc_profile;
    gsicc_rendering_param_t render_cond;   
    int code;

    if (cmm_icc_profile_data == NULL ) {
        code = dev_proc(dev, get_profile)(dev,  &dev_profile);
        gsicc_extract_profile(dev->graphics_type_tag, dev_profile,
                               &(icc_profile), &render_cond);
        *hash = icc_profile->hashcode;
        return;
    }
    if (cmm_icc_profile_data->hash_is_valid ) {
        *hash = cmm_icc_profile_data->hashcode;
        return;
    } else {
        /* We need to compute for this color space */
        gsicc_get_icc_buff_hash(cmm_icc_profile_data->buffer, hash,
                                cmm_icc_profile_data->buffer_size);
        cmm_icc_profile_data->hashcode = *hash;
        cmm_icc_profile_data->hash_is_valid = true;
        return;
    }
}

gsicc_link_t*
gsicc_findcachelink(gsicc_hashlink_t hash, gsicc_link_cache_t *icc_link_cache, 
                    bool includes_proof, bool includes_devlink)
{
    gsicc_link_t *curr, *prev;
    int64_t hashcode = hash.link_hashcode;

    /* Look through the cache for the hashcode */
    gx_monitor_enter(icc_link_cache->lock);

    /* List scanning is fast, so we scan the entire list, this includes   */
    /* links that are currently unused, but still in the cache (zero_ref) */
    curr = icc_link_cache->head;
    prev = NULL;

    while (curr != NULL ) {
        if (curr->hashcode.link_hashcode == hashcode && 
            includes_proof == curr->includes_softproof &&
            includes_devlink == curr->includes_devlink) {
            /* move this one to the front of the list hoping we will use it 
               again soon */
            if (prev != NULL) {		
                /* if prev == NULL, curr is already the head */
                prev->next = curr->next;
                curr->next = icc_link_cache->head;
                icc_link_cache->head = curr;
            }
            curr->ref_count++;		
            /* bump the ref_count since we will be using this one */
            while (curr->valid == false) {
                curr->num_waiting++;
                gx_monitor_leave(icc_link_cache->lock);
                gx_semaphore_wait(curr->wait);
                gx_monitor_enter(icc_link_cache->lock);	/* re-enter breifly */
            }
            gx_monitor_leave(icc_link_cache->lock);
            return(curr);	/* success */
        }
        prev = curr;
        curr = curr->next;
    }
    gx_monitor_leave(icc_link_cache->lock);
    return NULL;
}

/* Find entry with zero ref count and remove it */
/* lock the cache during this time for multi-threaded case */
/* This may release links waiting for an icc_link_cache slot */
static gsicc_link_t*
gsicc_find_zeroref_cache(gsicc_link_cache_t *icc_link_cache)
{
    gsicc_link_t *curr = NULL;

    /* Look through the cache for first zero ref count */
    /* when ref counts go to zero, the icc_link is moved to the */
    /* end of the list, so the first we find is the 'oldest'.
       If we get to the last entry we return NULL.  At that point
       there are no slots available and the thread should be
       put into a wait state.  Since most threads have at most 1 active
       link at anyone time, this will not be an issue for a single-threaded
       case. */

    curr = icc_link_cache->head;
    while (curr != NULL ) {
        if (curr->ref_count == 0) {
            curr->ref_count++;		/* we will use this one */
            break;
        }
        curr = curr->next;
    }
    return(curr);
}

/* Remove link from cache.  Notify CMS and free */
static void
gsicc_remove_link(gsicc_link_t *link, gs_memory_t *memory)
{
    gsicc_link_t *curr, *prev;
    gsicc_link_cache_t *icc_link_cache = link->icc_link_cache;

    if_debug2m(gs_debug_flag_icc, memory,
               "[icc] Removing link = 0x%x memory = 0x%x\n", link,
               memory->stable_memory);
    /* NOTE: link->ref_count must be 0: assert ? */
    gx_monitor_enter(icc_link_cache->lock);
    curr = icc_link_cache->head;
    prev = NULL;

    while (curr != NULL ) {
        if (curr == link) {
            /* remove this one from the list */
            if (prev == NULL)
                icc_link_cache->head = curr->next;
            else
                prev->next = curr->next;
            break;
        }
        prev = curr;
        curr = curr->next;
    }
    /* if curr != link we didn't find it: assert ? */
    gx_monitor_leave(icc_link_cache->lock);
    gsicc_link_free(link, memory);	/* outside link */
}

gsicc_link_t*
gsicc_get_link(const gs_imager_state *pis, gx_device *dev_in,
               const gs_color_space *pcs_in,
               gs_color_space *output_colorspace,
               gsicc_rendering_param_t *rendering_params, gs_memory_t *memory)
{
    cmm_profile_t *gs_input_profile;
    cmm_profile_t *gs_srcgtag_profile = NULL;
    cmm_profile_t *gs_output_profile;
    gs_state *pgs;
    gx_device *dev;
    gsicc_rendering_param_t render_cond; 
    cmm_dev_profile_t *dev_profile;
    int code;
    bool devicegraytok;
    gs_color_space *input_colorspace = (gs_color_space*) pcs_in;

    if (dev_in == NULL) {
        /* Get from the imager state which is going to be a graphic state.
           This only occurs for the other (non-ps/pdf) interpreters */
        pgs = (gs_state*) pis;
        dev = pgs->device;
    } else {
        dev = dev_in;
    }
    if (input_colorspace->cmm_icc_profile_data == NULL) {
        if (input_colorspace->icc_equivalent != NULL) {
            gs_input_profile = input_colorspace->icc_equivalent->cmm_icc_profile_data;        
        } else {
            /* Use default type */
            gs_input_profile = gsicc_get_gscs_profile(input_colorspace, 
                                                      pis->icc_manager);
        }
    } else {
        gs_input_profile = input_colorspace->cmm_icc_profile_data;
    }
    code = dev_proc(dev, get_profile)(dev,  &dev_profile);
    /* If present, use an graphic object defined source profile */
    if (pis->icc_manager != NULL && 
        pis->icc_manager->srcgtag_profile != NULL) {
            if (gs_input_profile->data_cs == gsRGB
                || gs_input_profile->data_cs == gsCMYK) {
                gsicc_get_srcprofile(gs_input_profile->data_cs,
                                      dev->graphics_type_tag,
                                      pis->icc_manager->srcgtag_profile,
                                      &(gs_srcgtag_profile), &render_cond);
                if (gs_srcgtag_profile != NULL) {
                    /* In this case, the user is letting the source profiles
                       drive the color management.  Let that set the 
                       rendering intent and blackpoint compensation also as they 
                       must know what they are doing.  However, before we do
                       this we need to check if they want to overide 
                       embedded source profiles.   See if our profile is a 
                       default one that came from DefaultRGB or DefaultCMYK
                       for example */
                    int csi;
                        
                    csi = gsicc_get_default_type(gs_input_profile);
                    if (render_cond.override_icc || 
                        csi == gs_color_space_index_DeviceRGB ||
                        csi == gs_color_space_index_DeviceCMYK) {
                        gs_input_profile = gs_srcgtag_profile;
                        (*rendering_params) = render_cond;
                    }
                    /* We also need to worry about the case when the source
                       profile is actually a device link profile.  In this case
                       we can go ahead now and the our link transform as we
                       don't need to worry about a destination profile.  
                       However, it is possible that someone could do another
                       device link profile associated with the device. */
                    if (gs_input_profile->isdevlink) {
                        /* OK. Go ahead and use this one.  Note output profile
                           is not NULL so that we can compute a hash with out
                           special conditional logic */
                        rendering_params->rendering_intent = 
                            render_cond.rendering_intent & gsRI_MASK;
                        rendering_params->black_point_comp = 
                            render_cond.black_point_comp & gsBP_MASK;

                            return gsicc_get_link_profile(pis, dev, gs_input_profile, 
                                                          dev_profile->device_profile[0], 
                                                          rendering_params, memory, 
                                                          false);
                    }
                } else {
                    /* In this case we may be wanting for a "unmanaged color"
                       result. This is done by specifying "None" on the 
                       particular line for that source object.  Check if this
                       is what is desired.  If it is, then return the link now.
                       Also need to worry about the replace case */
                    if (render_cond.cmm == gsCMM_NONE) {
                        gsicc_link_t *link;

                        if (gs_input_profile->data_cs == gsRGB) {
                            link = gsicc_nocm_get_link(pis, dev, 3);
                        } else {
                            link = gsicc_nocm_get_link(pis, dev, 4);
                        }
                        /* Set the identity case if we are in that situation */
                        if (link != NULL) {
                            if (gs_input_profile->num_comps == 
                                dev_profile->device_profile[0]->num_comps) {
                                link->is_identity = true;
                            }
                            return link;
                        }
                    } else if (render_cond.cmm == gsCMM_REPLACE) {
                        return gsicc_rcm_get_link(pis, dev, 
                                                  gs_input_profile->data_cs);
                        /* Note that there is never an identity case  */
                    }
                }
            }
    }
    if (output_colorspace != NULL) {
        gs_output_profile = output_colorspace->cmm_icc_profile_data;
        devicegraytok = false;
    } else {
        /* Use the device profile. Only use the rendering intent if it has 
           an override setting.  Also, only use the blackpoint if overide_bp 
           is set. Note that this can conflict with intents set from the source
           objects so the user needs to understand what options to set. */
        gs_color_space_index index = 
                            gsicc_get_default_type(gs_input_profile);
        code = dev_proc(dev, get_profile)(dev,  &dev_profile);
        /* Check for unmanaged color case */
        if (index < gs_color_space_index_DevicePixel && 
            dev_profile->usefastcolor) {
            /* Return a "link" from the source space to the device color space */
            gsicc_link_t *link = gsicc_nocm_get_link(pis, dev, 
                                                     gs_input_profile->num_comps);
            if (link != NULL) {
                if (gs_input_profile->num_comps == 
                    dev_profile->device_profile[0]->num_comps) {
                    link->is_identity = true;
                }
                return link;
            }
        }
        gsicc_extract_profile(dev->graphics_type_tag, dev_profile,
                               &(gs_output_profile), &render_cond);
        /* Check if the incoming rendering intent was source based
           (this can occur for high level images in the clist) in
           that case we need to use the source ri and not the device one */
        if (!(rendering_params->rendering_intent & gsRI_OVERRIDE)) {
            /* No it was not.  Check if our device profile RI was specified */
            if (render_cond.rendering_intent != gsRINOTSPECIFIED) {
                rendering_params->rendering_intent = render_cond.rendering_intent;      
            }
        }
        /* Similar for the black point compensation */
        if (!(rendering_params->black_point_comp & gsBP_OVERRIDE)) {
            if (render_cond.black_point_comp != gsBPNOTSPECIFIED) {
                rendering_params->black_point_comp = render_cond.black_point_comp;      
            }
        }
        /* And the Black preservation */
        if (!(rendering_params->preserve_black & gsKP_OVERRIDE)) {
            if (render_cond.preserve_black != gsBPNOTSPECIFIED) {
                rendering_params->preserve_black = render_cond.preserve_black;      
            }
        }
        devicegraytok = dev_profile->devicegraytok;
    }
    /* If we are going from DeviceGray to DeviceCMYK and devicegraytok
       is true then use the ps_gray and ps_cmyk profiles instead of these
       profiles */
    rendering_params->rendering_intent = rendering_params->rendering_intent & gsRI_MASK;
    rendering_params->black_point_comp = rendering_params->black_point_comp & gsBP_MASK;
    rendering_params->preserve_black = rendering_params->preserve_black & gsKP_MASK;
    return gsicc_get_link_profile(pis, dev, gs_input_profile, gs_output_profile,
                    rendering_params, memory, devicegraytok);
}

/* This operation of adding in a new link entry is actually shared amongst
   different functions that can each add an entry.  For example, entrys may
   come from the CMM or they may come from the non color managed approach 
   (i.e. gsicc_nocm_get_link) */
bool
gsicc_alloc_link_entry(gsicc_link_cache_t *icc_link_cache, 
                       gsicc_link_t **ret_link, gsicc_hashlink_t hash,
                       bool include_softproof, bool include_devlink)
{
    gs_memory_t *cache_mem = icc_link_cache->memory;
    gsicc_link_t *link;

    /* First see if we can add a link */
    /* TODO: this should be based on memory usage, not just num_links */
    gx_monitor_enter(icc_link_cache->lock);
    while (icc_link_cache->num_links >= ICC_CACHE_MAXLINKS) {
        /* If not, see if there is anything we can remove from cache. */
        while ((link = gsicc_find_zeroref_cache(icc_link_cache)) == NULL) {
            icc_link_cache->num_waiting++;
            /* safe to unlock since above will make sure semaphore is signalled */
            gx_monitor_leave(icc_link_cache->lock);
            /* we get signalled (released from wait) when a link goes to zero ref */
            gx_semaphore_wait(icc_link_cache->wait);
            /* repeat the findcachelink to see if some other thread has	*/
            /*already started building the link	we need			*/
            *ret_link = gsicc_findcachelink(hash, icc_link_cache, 
                                            include_softproof, include_devlink);
            /* Got a hit, return link (ref_count for the link was already bumped */
            if (*ret_link != NULL)
                return true;  
            gx_monitor_enter(icc_link_cache->lock);	    /* restore the lock */
            /* we will re-test the num_links above while locked to insure */
            /* that some other thread didn't grab the slot and max us out */
        }
        /* Remove the zero ref_count link profile we found.		*/
        /* Even if we remove this link, we may still be maxed out so	*/
        /* the outermost 'while' will check to make sure some other	*/
        /* thread did not grab the one we remove.			*/
        gsicc_remove_link(link, cache_mem);
        icc_link_cache->num_links--;
    }
    /* insert an empty link that we will reserve so we */
    /* can unlock while building the link contents     */
    (*ret_link) = gsicc_alloc_link(cache_mem->stable_memory, hash);
    if (*ret_link) {
        (*ret_link)->icc_link_cache = icc_link_cache;
        (*ret_link)->next = icc_link_cache->head;
        icc_link_cache->head = *ret_link;
        icc_link_cache->num_links++;
        /* now that we own this link we can release
          the lock since it is not valid */
    }
    gx_monitor_leave(icc_link_cache->lock);
    return false;
}

/* This is the main function called to obtain a linked transform from the ICC 
   cache If the cache has the link ready, it will return it.  If not, it will 
   request one from the CMS and then return it.  We may need to do some cache 
   locking during this process to avoid multi-threaded issues (e.g. someone 
   deleting while someone is updating a reference count).  Note that if the
   source profile is a device link profile we have no output profile but
   may still have a proofing or another device link profile to use */
gsicc_link_t*
gsicc_get_link_profile(const gs_imager_state *pis, gx_device *dev,
                       cmm_profile_t *gs_input_profile,
                       cmm_profile_t *gs_output_profile,
                       gsicc_rendering_param_t *rendering_params,
                       gs_memory_t *memory, bool devicegraytok)
{
    gsicc_hashlink_t hash;
    gsicc_link_t *link, *found_link;
    gcmmhlink_t link_handle = NULL;
    gsicc_manager_t *icc_manager = pis->icc_manager;
    gsicc_link_cache_t *icc_link_cache = pis->icc_link_cache;
    gs_memory_t *cache_mem = pis->icc_link_cache->memory;
    gcmmhprofile_t *cms_input_profile;
    gcmmhprofile_t *cms_output_profile = NULL;
    gcmmhprofile_t *cms_proof_profile = NULL;
    gcmmhprofile_t *cms_devlink_profile = NULL;
    int code;
    bool include_softproof = false;
    bool include_devicelink = false;
    cmm_dev_profile_t *dev_profile;
    cmm_profile_t *proof_profile = NULL;
    cmm_profile_t *devlink_profile = NULL;
    bool src_dev_link = gs_input_profile->isdevlink;
    bool pageneutralcolor = false;
    int cms_flags = 0;

    /* Determine if we are using a soft proof or device link profile */
    if (dev != NULL ) {
        code = dev_proc(dev, get_profile)(dev,  &dev_profile);
        if (dev_profile != NULL) {
            proof_profile = dev_profile->proof_profile;
            devlink_profile = dev_profile->link_profile;
            pageneutralcolor = dev_profile->pageneutralcolor;
        }
        /* If the source color is the same as the proofing color then we do not 
           need to apply the proofing color in this case.  This occurs in cases
           where we have a CMYK output intent profile, a Device CMYK color, and
           are going out to an RGB device */
        if (proof_profile != NULL ) {
            if (proof_profile->hashcode == gs_input_profile->hashcode) {
                proof_profile = NULL;
            } else {
                include_softproof = true;
            }
        }
        if (devlink_profile != NULL) include_devicelink = true;
    }
    /* First compute the hash code for the incoming case.  If the output color 
       space is NULL we will use the device profile for the output color space */
    gsicc_compute_linkhash(icc_manager, dev, gs_input_profile, gs_output_profile,
                            rendering_params, &hash);
    /* Check the cache for a hit.  Need to check if softproofing was used */
    found_link = gsicc_findcachelink(hash, icc_link_cache, include_softproof,
                                     include_devicelink);
    /* Got a hit, return link (ref_count for the link was already bumped */
    if (found_link != NULL) {
        if_debug2m(gs_debug_flag_icc, memory,
                   "[icc] Found Link = 0x%x, hash = %I64d \n", 
                   found_link, hash.link_hashcode);
        if_debug2m(gs_debug_flag_icc, memory,
                   "[icc] input_numcomps = %d, input_hash = %I64d \n",
                   gs_input_profile->num_comps, gs_input_profile->hashcode);
        if_debug2m(gs_debug_flag_icc, memory,
                   "[icc] output_numcomps = %d, output_hash = %I64d \n",
                   gs_output_profile->num_comps, gs_output_profile->hashcode);
        return found_link;
    }
    /* Before we do anything, check if we have a case where the source profile
       is coming from the clist and we don't even want to be doing any color
       managment */
    if (gs_input_profile->profile_handle == NULL && 
        gs_input_profile->buffer == NULL &&
        gs_input_profile->dev != NULL) {

        /* ICC profile should be in clist. This is the first call to it.  Note that 
           the profiles are not really shared amongst threads like the links are.  
           Hence the memory is for the local thread's chunk */
        cms_input_profile =
            gsicc_get_profile_handle_clist(gs_input_profile,
                                           gs_input_profile->memory);
        gs_input_profile->profile_handle = cms_input_profile;
        /* It is possible that we are not using color management
           due to a setting forced from srcgtag object (the None option)
           which has made its way though the clist in the clist imaging 
           code.   In this case, the srcgtag_profile structure
           which was part of the ICC manager is no longer available.
           We also have the Replace option.  */
        if (gs_input_profile->rend_is_valid &&
            gs_input_profile->rend_cond.cmm == gsCMM_NONE) {

            if (gs_input_profile->data_cs == gsRGB) {
                link = gsicc_nocm_get_link(pis, dev, 3);
            } else {
                link = gsicc_nocm_get_link(pis, dev, 4);
            }
            /* Set the identity case if we are in that situation */
            if (link != NULL) {
                if (gs_input_profile->num_comps == 
                    dev_profile->device_profile[0]->num_comps) {
                    link->is_identity = true;
                }
                return link;
            }
        } else if (gs_input_profile->rend_is_valid &&
            gs_input_profile->rend_cond.cmm == gsCMM_REPLACE) {
            return gsicc_rcm_get_link(pis, dev, gs_input_profile->data_cs);
            /* Note that there is never an identity case for
               this type.  */
        }    
        /* We may have a source profile that is a device link profile and
           made its way through the clist.  If so get things set up to 
           handle that properly. */
        src_dev_link = gs_input_profile->isdevlink;
    }
    /* No link was found so lets create a new one if there is room. This may 
       actually return a link if another thread has already created it */
    if (gsicc_alloc_link_entry(icc_link_cache, &link, hash, include_softproof,
                               include_devicelink)) 
        return link;
    if (link == NULL)
        return NULL;

    /* Now compute the link contents */
    cms_input_profile = gs_input_profile->profile_handle;
    /*  Check if the source was generated from a PS CIE color space.  If yes, 
        then we need to make sure that the CMM does not do something like 
        force a white point mapping like lcms does */
    if (gsicc_profile_from_ps(gs_input_profile)) {
        cms_flags = cms_flags | gscms_avoid_white_fix_flag(); 
    } 
    if (cms_input_profile == NULL) {
        if (gs_input_profile->buffer != NULL) {
            cms_input_profile =
                gsicc_get_profile_handle_buffer(gs_input_profile->buffer,
                                                gs_input_profile->buffer_size,
                                                memory);
            if (cms_input_profile == NULL)
                return NULL;
            gs_input_profile->profile_handle = cms_input_profile;
            if (cms_input_profile == NULL)
                return NULL;
            /* This *must* be a default profile that was not set up at start-up/
               However it could be one from the icc creator code which does not
               do an initialization at the time of creation from CalRGB etc. */
            code = gsicc_initialize_default_profile(gs_input_profile); 
            if (code < 0) return NULL;
        } else {
            /* Cant create the link.  No profile present,
               nor any defaults to use for this.  Really
               need to throw an error for this case. */
            gsicc_remove_link(link, cache_mem);
            icc_link_cache->num_links--;
            return NULL;
        }
    }
    /* No need to worry about an output profile handle if our source is a
       device link profile */
    if (!src_dev_link) {
        cms_output_profile = gs_output_profile->profile_handle;
    }
    if (cms_output_profile == NULL && !src_dev_link) {
        if (gs_output_profile->buffer != NULL) {
            cms_output_profile =
                gsicc_get_profile_handle_buffer(gs_output_profile->buffer,
                                                gs_output_profile->buffer_size,
                                                memory);
            gs_output_profile->profile_handle = cms_output_profile;
            /* This *must* be a default profile that was not set up at start-up */
            code = gsicc_initialize_default_profile(gs_output_profile); 
            if (code < 0) return NULL;
        } else {
              /* See if we have a clist device pointer. */
            if ( gs_output_profile->dev != NULL ) {
                /* ICC profile should be in clist. This is
                   the first call to it. */
                cms_output_profile =
                    gsicc_get_profile_handle_clist(gs_output_profile,
                                                   gs_output_profile->memory);
                gs_output_profile->profile_handle = cms_output_profile;
            } else {
                /* Cant create the link.  No profile present,
                   nor any defaults to use for this.  Really
                   need to throw an error for this case. */
                gsicc_remove_link(link, cache_mem);
                icc_link_cache->num_links--;
                return NULL;
            }
        }
    }
    if (include_softproof) {
        cms_proof_profile = proof_profile->profile_handle;
        if (cms_proof_profile == NULL) {
            if (proof_profile->buffer != NULL) {
                cms_proof_profile =
                    gsicc_get_profile_handle_buffer(proof_profile->buffer,
                                                    proof_profile->buffer_size,
                                                    memory);
                proof_profile->profile_handle = cms_proof_profile;
                gx_monitor_enter(proof_profile->lock);
            } else {
                /* Cant create the link */
                gsicc_remove_link(link, cache_mem);
                icc_link_cache->num_links--;
                return NULL;
            }
        }
    }
    if (include_devicelink) {
        cms_devlink_profile = devlink_profile->profile_handle;
        if (cms_devlink_profile == NULL) {
            if (devlink_profile->buffer != NULL) {
                cms_devlink_profile =
                    gsicc_get_profile_handle_buffer(devlink_profile->buffer,
                                                    devlink_profile->buffer_size,
                                                    memory);
                devlink_profile->profile_handle = cms_devlink_profile;
                gx_monitor_enter(devlink_profile->lock);
            } else {
                /* Cant create the link */
                gsicc_remove_link(link, cache_mem);
                icc_link_cache->num_links--;
                return NULL;
            }
        }
    }
    /* Profile reading of same structure not thread safe in lcms */
    gx_monitor_enter(gs_input_profile->lock);
    if (!src_dev_link) {
        gx_monitor_enter(gs_output_profile->lock);
    }
    /* We may have to worry about special handling for DeviceGray to
       DeviceCMYK to ensure that Gray is mapped to K only.  This is only
       done once and then it is cached and the link used */
    if (!src_dev_link && gs_output_profile->data_cs == gsCMYK && 
        gs_input_profile->data_cs == gsGRAY && pis->icc_manager != NULL &&
        devicegraytok) {
        if (icc_manager->graytok_profile == NULL) {
            icc_manager->graytok_profile =
                gsicc_set_iccsmaskprofile(GRAY_TO_K, strlen(GRAY_TO_K), 
                                          pis->icc_manager,
                                          pis->icc_manager->memory->stable_memory);
            if (icc_manager->graytok_profile == NULL) {
                return NULL;
            }
        }
        if (icc_manager->smask_profiles == NULL) {
            code = gsicc_initialize_iccsmask(icc_manager);
        }
        cms_input_profile = 
            icc_manager->smask_profiles->smask_gray->profile_handle;
        cms_output_profile = 
            icc_manager->graytok_profile->profile_handle;
        /* Turn off bp compensation in this case as there is a bug in lcms */
        rendering_params->black_point_comp = false;
        cms_flags = 0;  /* Turn off any flag setting */
    }
    /* Get the link with the proof and or device link profile */
    if (include_softproof || include_devicelink || src_dev_link) {
        link_handle = gscms_get_link_proof_devlink(cms_input_profile,
                                                   cms_proof_profile,
                                                   cms_output_profile,
                                                   cms_devlink_profile,
                                                   rendering_params,
                                                   src_dev_link, cms_flags,
                                                   cache_mem->non_gc_memory);
        if (include_softproof) {
            gx_monitor_leave(proof_profile->lock);
        }
        if (include_devicelink) {
            gx_monitor_leave(devlink_profile->lock);
        }
    } else {
        link_handle = gscms_get_link(cms_input_profile, cms_output_profile,
                                     rendering_params, cms_flags, 
                                     cache_mem->non_gc_memory);
    }
    if (!src_dev_link) {
        gx_monitor_leave(gs_output_profile->lock);
    }
    gx_monitor_leave(gs_input_profile->lock);
    if (link_handle != NULL) {
        if (gs_input_profile->data_cs == gsGRAY) 
            pageneutralcolor = false;
        gsicc_set_link_data(link, link_handle, hash, icc_link_cache->lock,
                            include_softproof, include_devicelink, pageneutralcolor, 
                            gs_input_profile->data_cs);
        if_debug2m(gs_debug_flag_icc, cache_mem,
                   "[icc] New Link = 0x%x, hash = %I64d \n", 
                   link, hash.link_hashcode);
        if_debug2m(gs_debug_flag_icc, cache_mem,
                   "[icc] input_numcomps = %d, input_hash = %I64d \n",
                   gs_input_profile->num_comps, gs_input_profile->hashcode);
        if_debug2m(gs_debug_flag_icc, cache_mem,
                   "[icc] output_numcomps = %d, output_hash = %I64d \n",
                   gs_output_profile->num_comps, gs_output_profile->hashcode);
    } else {
        gsicc_remove_link(link, cache_mem);
        icc_link_cache->num_links--;
        return NULL;
    }
    return link;
}

/* The following is used to transform a named color value at a particular tint
   value to the output device values.  This function is provided only as a
   demonstration and will likely need to be altered and optimized for those wishing
   to perform full spot color look-up support.

   The object used to perform the transformation is typically
   a look-up table that contains the spot color name and a CIELAB value for
   100% colorant (it could also contain device values in the table).
   It can be more complex where-by you have a 1-D lut that
   provides CIELAB values or direct device values as a function of tint.  In
   such a case, the table would be interpolated to compute all possible tint values.
   If CIELAB values are provided, they can be pushed through the
   device profile using the CMM.  In this particular demonstration, we simply
   provide CIELAB for a few color names in the file
   toolbin/color/named_color/named_color_table.txt .
   The tint value is used to scale the CIELAB value from 100% colorant to a D50
   whitepoint.  The resulting CIELAB value is then pushed through the CMM to
   obtain device values for the current device.  The file named_colors.pdf
   which is in toolbin/color/named_color/ contains these
   spot colors and will enable the user to see how the code behaves.  The named
   color table is specified to ghostscript by the command line option
   -sNamedProfile=./toolbin/color/named_color/named_color_table.txt (or with
   full path name).  If it is desired to have ghostscript compiled with the
   named color table, it can be placed in the iccprofiles directory and then
   build ghostscript with COMPILE_INITS=1.  When specified the file contents
   are pointed to by the buffer member variable of the device_named profile in
   profile manager.  When the first call occurs in here, the contents of the
   buffer are parsed and placed into a custom stucture that is pointed to by
   the profile pointer.  Note that this pointer is not visible to the garbage
   collector and should be allocated in non-gc memory as is demonstrated in
   this sample.  The structure elements are released when the profile is 
   destroyed through the call to gsicc_named_profile_release, which is set
   as the value of the profile member variable release.

   Note that there are calls defined in gsicc_littlecms.c that will create link
   transforms between Named Color ICC profiles and the output device.  Such
   profiles are rarely used (at least I have not run across any yet) so the
   code is currently not used.  Also note that for those serious about named
   color support, a cache as well as efficient table-look-up methods would
   likely be important for performance.

   Finally note that PANTONE is a registered trademark and PANTONE colors are a
   licensed product of XRITE Inc. See http://www.pantone.com
   for more information.  Licensees of Pantone color libraries or similar
   libraries should find it straight forward to interface.  Pantone names are
   referred to in named_color_table.txt and contained in the file named_colors.pdf.

   !!!!IT WILL BE NECESSARY TO PERFORM THE PROPER DEALLOCATION
       CLEAN-UP OF THE STRUCTURES WHEN rc_free_icc_profile OCCURS FOR THE NAMED
       COLOR PROFILE!!!!!!   See gsicc_named_profile_release below for an example.
       This is set in the profile release member variable.
*/

/* Define the demo structure and function for named color look-up */

typedef struct gsicc_namedcolortable_s {
    gsicc_namedcolor_t *named_color;    /* The named color */
    unsigned int number_entries;        /* The number of entries */
    gs_memory_t *memory;
} gsicc_namedcolortable_t;

/* Support functions for parsing buffer */

static int
get_to_next_line(char **buffptr, int *buffer_count)
{
    while (1) {
        if (**buffptr == ';') {
            (*buffptr)++;
            (*buffer_count)--;
            return(0);
        } else {
            (*buffptr)++;
            (*buffer_count)--;
        }
        if (*buffer_count <= 0) {
            return -1;
        }
    }
}

/* Release the structures we allocated in gsicc_transform_named_color */
static void
gsicc_named_profile_release(void *ptr)
{
    gsicc_namedcolortable_t *namedcolor_table = (gsicc_namedcolortable_t*) ptr;
    unsigned int num_entries;
    gs_memory_t *mem;
    int k;
    gsicc_namedcolor_t *namedcolor_data;

    if (namedcolor_table != NULL) {
        mem = namedcolor_table->memory;
        num_entries = namedcolor_table->number_entries;
        namedcolor_data = namedcolor_table->named_color;

        for (k = 0; k < num_entries; k++) {
            gs_free(mem, namedcolor_data[k].colorant_name, 1,
                namedcolor_data[k].name_size + 1,
                "gsicc_named_profile_release (colorant_name)");
        }

        gs_free(mem, namedcolor_data, num_entries, sizeof(gsicc_namedcolor_t),
            "gsicc_named_profile_release (namedcolor_data)");

        gs_free(namedcolor_table->memory, namedcolor_table, 1,
            sizeof(gsicc_namedcolortable_t),
            "gsicc_named_profile_release (namedcolor_table)");
    }
}

/* Function returns -1 if a name is not found.  Otherwise it will transform
   the named colors and return 0 */
int
gsicc_transform_named_color(const float tint_values[],
                            gsicc_namedcolor_t color_names[], 
                            uint num_names,
                            gx_color_value device_values[],
                            const gs_imager_state *pis, gx_device *dev,
                            cmm_profile_t *gs_output_profile,
                            gsicc_rendering_param_t *rendering_params)
{
    gsicc_namedcolor_t *namedcolor_data;
    unsigned int num_entries;
    cmm_profile_t *named_profile;
    gsicc_namedcolortable_t *namedcolor_table;
    int num_nonnone_names;
    int k,j,n;
    float lab[3];
    char *buffptr;
    int buffer_count;
    int count;
    int code;
    char *pch, *temp_ptr;
    bool done;
    int curr_name_size;
    bool found_match;
    unsigned short psrc[GS_CLIENT_COLOR_MAX_COMPONENTS];
    unsigned short psrc_cm[GS_CLIENT_COLOR_MAX_COMPONENTS];
    unsigned short temp_lab[3];
    unsigned short *psrc_temp;
    float temp;
    unsigned short white_lab[3] = {65535, 32767, 32767};
    gsicc_link_t *icc_link;
    cmm_profile_t *curr_output_profile;
    gsicc_rendering_param_t render_cond;   
    cmm_dev_profile_t *dev_profile;
    int indices[GS_CLIENT_COLOR_MAX_COMPONENTS]; 
    gs_memory_t *nongc_mem = pis->memory->non_gc_memory;

    /* Check if the data that we have has already been generated. */
    if (pis->icc_manager != NULL) {
        if (pis->icc_manager->device_named != NULL) {
            named_profile = pis->icc_manager->device_named;
            if (named_profile->buffer != NULL &&
                named_profile->profile_handle == NULL) {
                /* Create the structure that we will use in searching */
                /*  Note that we do this in non-GC memory since the
                    profile pointer is not GC'd */
                namedcolor_table =
                    (gsicc_namedcolortable_t*) gs_malloc(nongc_mem, 1,
                                                    sizeof(gsicc_namedcolortable_t),
                                                    "gsicc_transform_named_color");
                if (namedcolor_table == NULL) 
                    return(gs_error_VMerror);
                namedcolor_table->memory = nongc_mem;
                /* Parse buffer and load the structure we will be searching */
                buffptr = (char*) named_profile->buffer;
                buffer_count = named_profile->buffer_size;
                count = sscanf(buffptr,"%d",&num_entries);
                if (num_entries < 1 || count == 0) {
                    gs_free(nongc_mem, namedcolor_table, 1,
                            sizeof(gsicc_namedcolortable_t),
                            "gsicc_transform_named_color");
                    return -1;
                }
                code = get_to_next_line(&buffptr,&buffer_count);
                if (code < 0) {
                    gs_free(nongc_mem, namedcolor_table, 1,
                            sizeof(gsicc_namedcolortable_t),
                            "gsicc_transform_named_color");
                    return -1;
                }
                namedcolor_data =
                    (gsicc_namedcolor_t*) gs_malloc(nongc_mem, num_entries,
                                                    sizeof(gsicc_namedcolor_t),
                                                    "gsicc_transform_named_color");
                if (namedcolor_data == NULL) {
                    gs_free(nongc_mem, namedcolor_table, num_entries,
                            sizeof(gsicc_namedcolortable_t),
                            "gsicc_transform_named_color");
                    return gs_error_VMerror;
                }
                namedcolor_table->number_entries = num_entries;
                namedcolor_table->named_color = namedcolor_data;
                for (k = 0; k < num_entries; k++) {
                    if (k == 0) {
                        pch = strtok(buffptr,",;");
                    } else {
                        pch = strtok(NULL,",;");
                    }
                    /* Remove any /0d /0a stuff from start */
                    temp_ptr = pch;
                    done = 0;
                    while (!done) {
                        if (*temp_ptr == 0x0d || *temp_ptr == 0x0a) {
                            temp_ptr++;
                        } else {
                            done = 1;
                        }
                    }
                    curr_name_size = strlen(temp_ptr);
                    namedcolor_data[k].name_size = curr_name_size;
                    /* +1 for the null */
                    namedcolor_data[k].colorant_name =
                        (char*)gs_malloc(nongc_mem, 1, curr_name_size + 1,
                                          "gsicc_transform_named_color");
                    if (namedcolor_data[k].colorant_name == NULL)
                        return gs_error_VMerror;
                    strncpy(namedcolor_data[k].colorant_name,temp_ptr,
                            namedcolor_data[k].name_size+1);
                    for (j = 0; j < 3; j++) {
                        pch = strtok(NULL,",;");
                        count = sscanf(pch,"%f",&(lab[j]));
                    }
                    lab[0] = lab[0]*65535/100.0;
                    lab[1] = (lab[1] + 128.0)*65535/255;
                    lab[2] = (lab[2] + 128.0)*65535/255;
                    for (j = 0; j < 3; j++) {
                        if (lab[j] > 65535) lab[j] = 65535;
                        if (lab[j] < 0) lab[j] = 0;
                        namedcolor_data[k].lab[j] = (unsigned short) lab[j];
                    }
                }
                /* Assign to the profile pointer */
                named_profile->profile_handle = namedcolor_table;
                named_profile->release = gsicc_named_profile_release;
            } else {
                if (named_profile->profile_handle != NULL ) {
                    namedcolor_table =
                        (gsicc_namedcolortable_t*) named_profile->profile_handle;
                   num_entries = namedcolor_table->number_entries;
                } else {
                    return -1;
                }
            }
            /* Go through each of our spot names, getting the color value for
               each one. */
            num_nonnone_names = num_names;
            for (n = 0; n < num_names; n++) {
                /* Search our structure for the color name.  Ignore the None
                   colorant names.  All is a special case that someone may 
                   want to detect and do some special handling for.  In this
                   particular example we would punt with All and let the default
                   methods handle it */
                found_match = false;

                if (strncmp("None", (const char *)color_names[n].colorant_name, 
                            color_names[n].name_size) == 0) {
                    num_nonnone_names--;
                } else {
                    /* Colorant was not None */
                    for (k = 0; k < num_entries; k++) {
                        if (color_names[n].name_size ==
                            namedcolor_table->named_color[k].name_size) {
                            if (strncmp((const char *)namedcolor_table->named_color[k].colorant_name,
                                (const char *)color_names[n].colorant_name, color_names[n].name_size) == 0) {
                                found_match = true;
                                break;
                            }
                        }
                    }
                    if (found_match) {
                        indices[n] = k;
                    } else {
                        /* We do not know this colorant, return -1 */
                        return -1;
                    }
                }
            }
            if (num_nonnone_names < 1)
                return -1; /* No non-None colorants. */
            /* We have all the colorants.  Lets go through and see if we can
               make something that looks like a merge of the various ones */
            /* Apply tint, blend LAB values.  Note that we may have wanted to 
               check if we even want to do this.  It is possible that the
               device directly supports this particular colorant.  One may
               want to check the alt tint transform boolean */
            for (n = 0; n < num_nonnone_names; n++) {
                for (j = 0; j < 3; j++) {
                    temp = (float) namedcolor_table->named_color[indices[n]].lab[j] * tint_values[n]
                            + (float) white_lab[j] * (1.0 - tint_values[n]);
                    temp_lab[j] = (unsigned short) temp;
                }
                /* Blend with the current color.  Note this is just for 
                   demonstration.  Much better methods are possible for this */
                if (n == 0) {
                    for (j = 0; j < 3; j++) {
                        psrc[j] = temp_lab[j];
                    }
                } else {
                    psrc[0] = (psrc[0]*temp_lab[0])/white_lab[0]; /* L* */
                    psrc[1] = (psrc[1] + temp_lab[1]) / 2; /* a* */
                    psrc[2] = (psrc[2] + temp_lab[2]) / 2; /* b* */
                }
            }
            /* Push LAB value through CMM to get CMYK device values */
            /* Note that there are several options here. You could us an NCLR 
               icc profile to compute the device colors that you want.  For,
               example if the output device had an NCLR profile.
               However, what you MUST do here is set ALL the device values.  
               Hence, below we initialize all of them to zero and in this 
               particular example, set only the ones that were output from 
               the device profile */
            if ( gs_output_profile != NULL ) {
                curr_output_profile = gs_output_profile;
            } else {
                /* Use the device profile.  Note if one was not set for the
                   device, the default CMYK profile is used.  Note that 
                   if we specified and NCLR profile it will be used here */
                code = dev_proc(dev, get_profile)(dev,  &dev_profile);
                gsicc_extract_profile(dev->graphics_type_tag,
                                      dev_profile, &(curr_output_profile),
                                      &render_cond);
            }
            icc_link = gsicc_get_link_profile(pis, dev,
                                            pis->icc_manager->lab_profile,
                                            curr_output_profile, rendering_params,
                                            pis->memory, false);
            if (icc_link->is_identity) {
                psrc_temp = &(psrc[0]);
            } else {
                /* Transform the color */
                psrc_temp = &(psrc_cm[0]);
                (icc_link->procs.map_color)(dev, icc_link, psrc, psrc_temp, 2);
            }
            gsicc_release_link(icc_link);

            /* Clear out ALL the color values */
            for (k = 0; k < dev->color_info.num_components; k++){
                device_values[k] = 0;
            }
            /* Set only the values that came from the profile.  By default
               this would generally be just CMYK values.  For the equivalent
               color computation case it certainly will be.  If someone 
               specified an NCLR profile it could be more.  Note that if an
               NCLR profile is being used we will want to make sure the colorant
               order is correct */
            for (k = 0; k < curr_output_profile->num_comps; k++){
                device_values[k] = psrc_temp[k];
            }
            return 0;
        }
    }
    return -1; /* Color not found */
}

/* Used by gs to notify the ICC manager that we are done with this link for now */
/* This may release elements waiting on an icc_link_cache slot */
void
gsicc_release_link(gsicc_link_t *icclink)
{
    gsicc_link_cache_t *icc_link_cache = icclink->icc_link_cache;

    gx_monitor_enter(icc_link_cache->lock);
    /* Decrement the reference count */
    if (--(icclink->ref_count) == 0) {

        gsicc_link_t *curr, *prev;

        /* Find link in cache, and move it to the end of the list.  */
        /* This way zero ref_count links are found LRU first	*/
        curr = icc_link_cache->head;
        prev = NULL;
        while (curr != icclink) {
            prev = curr;
            curr = curr->next;
        };
        if (prev == NULL) {
            /* this link was the head */
            icc_link_cache->head = curr->next;
        } else {
            prev->next = curr->next;		/* de-link this one */
        }
        /* Find the first zero-ref entry on the list */
        curr = icc_link_cache->head;
        prev = NULL;
        while (curr != NULL && curr->ref_count > 0) {
            prev = curr;
            curr = curr->next;
        }
        /* Found where to link this one into the tail of the list */
        if (prev == NULL) {
            icc_link_cache->head = icclink;
            icclink->next = icc_link_cache->head->next;
        } else {
            /* link this one in here */
            prev->next = icclink;
            icclink->next = curr;
        }

        /* now release any tasks waiting for a cache slot */
        while (icclink->icc_link_cache->num_waiting > 0) {
            gx_semaphore_signal(icclink->icc_link_cache->wait);
            icclink->icc_link_cache->num_waiting--;
        }
    }
    gx_monitor_leave(icc_link_cache->lock);
}

/* Used to initialize the buffer description prior to color conversion */
void
gsicc_init_buffer(gsicc_bufferdesc_t *buffer_desc, unsigned char num_chan, unsigned char bytes_per_chan,
                  bool has_alpha, bool alpha_first, bool is_planar, int plane_stride, int row_stride,
                  int num_rows, int pixels_per_row)
{
    buffer_desc->num_chan = num_chan;
    buffer_desc->bytes_per_chan = bytes_per_chan;
    buffer_desc->has_alpha = has_alpha;
    buffer_desc->alpha_first = alpha_first;
    buffer_desc->is_planar = is_planar;
    buffer_desc->plane_stride = plane_stride;
    buffer_desc->row_stride = row_stride;
    buffer_desc->num_rows = num_rows;
    buffer_desc->pixels_per_row = pixels_per_row;

    /* sample endianess is consistent across platforms */
    buffer_desc->little_endian = true;

}

/* Return the proper component numbers based upon the profiles of the device.
   This is in here since it is usually called when creating and using a link
   from the link cache. */
int 
gsicc_get_device_profile_comps(cmm_dev_profile_t *dev_profile)
{
    if (dev_profile->link_profile == NULL) {
       return dev_profile->device_profile[0]->num_comps;
    } else {
       return dev_profile->link_profile->num_comps_out;
    }
}