From 1b55efb5218c3a0d60265168a572240ce2c85b03 Mon Sep 17 00:00:00 2001 From: Heikki Levanto Date: Wed, 2 Jun 2004 17:26:03 +0000 Subject: [PATCH] Rewriting the isamb forward. Time being, new code is #ifdef'd out. Regular reads seem to work. forwarding is mostly missing, although there is some raw beginnings... --- isamb/isamb.c | 147 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 146 insertions(+), 1 deletion(-) diff --git a/isamb/isamb.c b/isamb/isamb.c index c46246a..af0a705 100644 --- a/isamb/isamb.c +++ b/isamb/isamb.c @@ -1,4 +1,4 @@ -/* $Id: isamb.c,v 1.37 2004-06-02 14:07:01 heikki Exp $ +/* $Id: isamb.c,v 1.38 2004-06-02 17:26:03 heikki Exp $ Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004 Index Data Aps @@ -1135,6 +1135,150 @@ int isamb_pp_read (ISAMB_PP pp, void *buf) } #endif +#define NEW_FORWARD 0 +#if NEW_FORWARD + + +static int isamb_pp_read_on_leaf(ISAMB_PP pp, void *buf) +{ /* reads the next item on the current leaf, returns 0 if end of leaf*/ + struct ISAMB_block *p = pp->block[pp->level]; + char *dst; + char *src; + if (p->offset == p->size) { +#if ISAMB_DEBUG + logf(LOG_DEBUG,"isamb_pp_read_on_leaf returning 0 on node %d",p->pos); +#endif + return 0; /* at end of leaf */ + } + src=p->bytes + p->offset; + dst=buf; + (*pp->isamb->method->code_item) + (ISAMC_DECODE, p->decodeClientData,&dst, &src); + p->offset = src - (char*) p->bytes; +#if ISAMB_DEBUG + (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "read_on_leaf returning 1"); +#endif + return 1; +} /* read_on_leaf */ + + +static int isamb_pp_climb_level(ISAMB_PP pp, int *pos) +{ /* climbs higher in the tree, until finds a level with data left */ + /* returns teh node to (consider to) descend to in *pos) */ + struct ISAMB_block *p = pp->block[pp->level]; + char *src; + int item_len; + assert(p->offset <= p->size); + if (pp->level==0) + { +#if ISAMB_DEBUG + logf(LOG_DEBUG,"isamb_pp_climb_level returning 0 at root"); + return 0; +#endif + } + close_block(pp->isamb, pp->block[pp->level]); + pp->block[pp->level]=0; + (pp->level)--; + p=pp->block[pp->level]; + logf(LOG_DEBUG,"isamb_pp_climb_level climbed to node %d ofs=%d", + p->pos, p->offset); + assert (!p->leaf); + assert (p->offset <= p->size); + if (p->offset == p->size ) { + /* we came from the last pointer, climb on */ + if (!isamb_pp_climb_level(pp,pos)) + return 0; + p=pp->block[pp->level]; + } + /* skip the child we just came from */ + assert (p->offset < p->size ); + src=p->bytes + p->offset; + decode_ptr(&src, &item_len); + src += item_len; + decode_ptr(&src, pos); + p->offset=src - (char *)p->bytes; + return 1; +} /* climb_level */ + + +static void isamb_pp_descend_to_first_leaf(ISAMB_PP pp, int pos) +{ /* climbs down the tree, from pos, to the leftmost leaf */ + struct ISAMB_block *p = pp->block[pp->level]; + char *src; + assert(!p->leaf); + ++(pp->level); + p=open_block(pp->isamb, pos); + pp->block[pp->level]=p; + ++(pp->accessed_nodes[pp->maxlevel-pp->level]); + ++(pp->no_blocks); +#if ISAMB_DEBUG + logf(LOG_DEBUG,"isamb_pp_descend_to_first_leaf " + "got lev %d node %d lf=%d", + pp->level, p->pos, p->leaf); +#endif + if (p->leaf) + return; + assert (p->offset==0 ); + src=p->bytes + p->offset; + decode_ptr(&src, &pos); + p->offset=src-(char*)p->bytes; + isamb_pp_descend_to_first_leaf(pp,pos); +} /* descend_to_first_leaf */ + +static int isamb_pp_find_next_leaf(ISAMB_PP pp) +{ /* finds the next leaf by climbing up and down */ + int pos; + if (!isamb_pp_climb_level(pp,&pos)) + return 0; + isamb_pp_descend_to_first_leaf(pp, pos); + return 1; +} +static int isamb_pp_forward_on_leaf(ISAMB_PP pp, void *buf, const void *untilbuf) +{ /* forwards on the current leaf, returns 0 if not found */ + assert (!"FIXME - not done yet"); + return 0; +} /* forward_on_leaf */ + +static int isamb_pp_climb_desc(ISAMB_PP pp, void *buf, const void *untilbuf) +{ /* climbs up and descends to a leaf where values >= *untilbuf are found */ + assert (!"FIXME - not done yet"); + return 0; +} /* climb_desc */ + +int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf) +{ +#if ISAMB_DEBUG + struct ISAMB_block *p = pp->block[pp->level]; + assert(p->leaf); +#endif + untilbuf=0; /*FIXME - disabling the forward part */ + if (untilbuf) { + if (isamb_pp_forward_on_leaf( pp, buf, untilbuf)) + return 1; + if (! isamb_pp_climb_desc( pp, buf, untilbuf)) + return 0; /* could not find a leaf */ + do{ + if (isamb_pp_forward_on_leaf( pp, buf, untilbuf)) + return 1; + }while ( isamb_pp_find_next_leaf(pp)); + return 0; /* could not find at all */ + } + else { /* no untilbuf, a straight read */ + /* FIXME - this should be moved + * directly into the pp_read */ + /* keeping here now, to keep same + * interface as the old fwd */ + if (isamb_pp_read_on_leaf( pp, buf)) + return 1; + if (isamb_pp_find_next_leaf(pp)) + return isamb_pp_read_on_leaf(pp, buf); + else + return 0; + } +} /* isam_pp_forward (new version) */ + +#else + int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf) { /* pseudocode: @@ -1324,6 +1468,7 @@ int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf) } /* main loop */ } +#endif int isamb_pp_num (ISAMB_PP pp) { -- 1.7.10.4