diff options
Diffstat (limited to 'src/H5Shyper.c')
| -rw-r--r-- | src/H5Shyper.c | 100 |
1 files changed, 87 insertions, 13 deletions
diff --git a/src/H5Shyper.c b/src/H5Shyper.c index 54738ff..c6639d7 100644 --- a/src/H5Shyper.c +++ b/src/H5Shyper.c @@ -5780,37 +5780,70 @@ H5S_hyper_bounds(H5S_t *space, hsize_t *start, hsize_t *end) htri_t H5S_hyper_select_contiguous(const H5S_t *space) { - htri_t ret_value=FAIL; /* return value */ H5S_hyper_span_info_t *spans; /* Hyperslab span info node */ - H5S_hyper_span_t *span; /* Hyperslab span node */ - unsigned u; /* index variable */ + H5S_hyper_span_t *span; /* Hyperslab span node */ + unsigned u; /* index variable */ + unsigned small_contiguous, /* Flag for small contiguous block */ + large_contiguous; /* Flag for large contiguous block */ + htri_t ret_value=FALSE; /* return value */ FUNC_ENTER (H5S_hyper_select_contiguous, FAIL); assert(space); - /* Quicker check for a "regular" hyperslab selection */ + /* Check for a "regular" hyperslab selection */ if(space->select.sel_info.hslab.diminfo != NULL) { /* * For a regular hyperslab to be contiguous, it must have only one * block (i.e. count==1 in all dimensions) and the block size must be * the same as the dataspace extent's in all but the slowest changing - * dimension. + * dimension. (dubbed "large contiguous" block) + * + * OR + * + * The selection must have only one block (i.e. count==1) and the block + * size must be 1 in all but the fastest changing dimension. (dubbed + * "small contiguous" block) */ - ret_value=TRUE; /* assume true and reset if the dimensions don't match */ + + /* Initialize flags */ + large_contiguous=TRUE; /* assume true and reset if the dimensions don't match */ + small_contiguous=FALSE; /* assume false initially */ + + /* Check for a "large contigous" block */ for(u=1; u<space->extent.u.simple.rank; u++) { if(space->select.sel_info.hslab.diminfo[u].count>1 || space->select.sel_info.hslab.diminfo[u].block!=space->extent.u.simple.size[u]) { - ret_value=FALSE; + large_contiguous=FALSE; break; } /* end if */ } /* end for */ + + /* If we didn't find a large contiguous block, check for a small one */ + if(large_contiguous==FALSE) { + small_contiguous=TRUE; + for(u=0; u<(space->extent.u.simple.rank-1); u++) { + if(space->select.sel_info.hslab.diminfo[u].count>1 || space->select.sel_info.hslab.diminfo[u].block!=1) { + small_contiguous=FALSE; + break; + } /* end if */ + } /* end for */ + } /* end if */ + + /* Indicate true if it's either a large or small contiguous block */ + if(large_contiguous || small_contiguous) + ret_value=TRUE; } /* end if */ else { /* - * For a hyperslab to be contiguous, it's size must be the same as the - * dataspace extent's in all but the slowest changing dimension + * For a hyperslab to be contiguous, it must have only one block and + * (either it's size must be the same as the dataspace extent's in all + * but the slowest changing dimension + * OR + * block size must be 1 in all but the fastest changing dimension). */ - ret_value=TRUE; /* assume true and reset if the dimensions don't match */ + /* Initialize flags */ + large_contiguous=TRUE; /* assume true and reset if the dimensions don't match */ + small_contiguous=FALSE; /* assume false initially */ /* Get information for slowest changing information */ spans=space->select.sel_info.hslab.span_lst; @@ -5818,7 +5851,7 @@ H5S_hyper_select_contiguous(const H5S_t *space) /* If there are multiple spans in the slowest changing dimension, the selection isn't contiguous */ if(span->next!=NULL) - ret_value=FALSE; + large_contiguous=FALSE; else { /* Now check the rest of the dimensions */ if(span->down!=NULL) { @@ -5833,13 +5866,13 @@ H5S_hyper_select_contiguous(const H5S_t *space) /* Check that this is the only span and it spans the entire dimension */ if(span->next!=NULL) { - ret_value=FALSE; + large_contiguous=FALSE; break; } /* end if */ else { /* If this span doesn't cover the entire dimension, then this selection isn't contiguous */ if(((span->high-span->low)+1)!=(hssize_t)space->extent.u.simple.size[u]) { - ret_value=FALSE; + large_contiguous=FALSE; break; } /* end if */ else { @@ -5853,6 +5886,47 @@ H5S_hyper_select_contiguous(const H5S_t *space) } /* end while */ } /* end if */ } /* end else */ + + /* If we didn't find a large contiguous block, check for a small one */ + if(large_contiguous==FALSE) { + small_contiguous=TRUE; + + /* Get information for slowest changing information */ + spans=space->select.sel_info.hslab.span_lst; + span=spans->head; + + /* Current dimension working on */ + u=0; + + /* Cycle down the spans until we run out of down spans or find a non-contiguous span */ + while(spans!=NULL) { + span=spans->head; + + /* Check that this is the only span and it spans the entire dimension */ + if(span->next!=NULL) { + small_contiguous=FALSE; + break; + } /* end if */ + else { + /* If this span doesn't cover the entire dimension, then this selection isn't contiguous */ + if(u<(space->extent.u.simple.rank-1) && ((span->high-span->low)+1)!=1) { + small_contiguous=FALSE; + break; + } /* end if */ + else { + /* Walk down to the next span */ + spans=span->down; + + /* Increment dimension */ + u++; + } /* end else */ + } /* end else */ + } /* end while */ + } /* end if */ + + /* Indicate true if it's either a large or small contiguous block */ + if(large_contiguous || small_contiguous) + ret_value=TRUE; } /* end else */ FUNC_LEAVE (ret_value); |