CHECK_BYTE CHECK_CHAR FT_COMPONENT ftc_sbit_copy_bitmap ftc_snode_compare FTC_SNode_Compare ftc_snode_free FTC_SNode_Free ftc_snode_load FTC_SNode_New ftc_snode_new ftc_snode_weight

ftc_snode_compare ( FTC_Node  ftcsnode, FT_Pointer  ftcgquery, FTC_Cache  cache  ) Definition at line 320 of file ftcsbits.c. Referenced by FTC_SNode_Compare(). { FTC_SNode snode = (FTC_SNode)ftcsnode; FTC_GQuery gquery = (FTC_GQuery)ftcgquery; FTC_GNode gnode = FTC_GNODE( snode ); FT_UInt gindex = gquery->gindex; FT_Bool result; result = FT_BOOL( gnode->family == gquery->family && (FT_UInt)( gindex - gnode->gindex ) < snode->count ); if ( result ) { /* check if we need to load the glyph bitmap now */ FTC_SBit sbit = snode->sbits + ( gindex - gnode->gindex ); /* * The following code illustrates what to do when you want to * perform operations that may fail within a lookup function. * * Here, we want to load a small bitmap on-demand; we thus * need to call the `ftc_snode_load' function which may return * a non-zero error code only when we are out of memory (OOM). * * The correct thing to do is to use @FTC_CACHE_TRYLOOP and * @FTC_CACHE_TRYLOOP_END in order to implement a retry loop * that is capable of flushing the cache incrementally when * an OOM errors occur. * * However, we need to `lock' the node before this operation to * prevent it from being flushed within the loop. * * When we exit the loop, we unlock the node, then check the `error' * variable. If it is non-zero, this means that the cache was * completely flushed and that no usable memory was found to load * the bitmap. * * We then prefer to return a value of 0 (i.e., NO MATCH). This * ensures that the caller will try to allocate a new node. * This operation consequently _fail_ and the lookup function * returns the appropriate OOM error code. * * Note that `buffer == NULL && width == 255' is a hack used to * tag `unavailable' bitmaps in the array. We should never try * to load these. * */ if ( sbit->buffer == NULL && sbit->width != 255 ) { FT_ULong size; FT_Error error; ftcsnode->ref_count++; /* lock node to prevent flushing */ /* in retry loop */ FTC_CACHE_TRYLOOP( cache ) { error = ftc_snode_load( snode, cache->manager, gindex, &size ); } FTC_CACHE_TRYLOOP_END(); ftcsnode->ref_count--; /* unlock the node */ if ( error ) result = 0; else cache->manager->cur_weight += size; } } return result; }