X-Git-Url: http://git.indexdata.com/?p=idzebra-moved-to-github.git;a=blobdiff_plain;f=isamb%2Fisamb.c;h=c0940ad067ad58ec46dd402f9f7da549af11c7ef;hp=15a825e8e93205170b15768968b1241cacc1c643;hb=764b78fb481cf1084a5a583ffefbe8a0f32af28c;hpb=289af445bf7c8042b46200f9f2af18049ae049fb

diff --git a/isamb/isamb.c b/isamb/isamb.c
index 15a825e..c0940ad 100644
--- a/isamb/isamb.c
+++ b/isamb/isamb.c
@@ -1,142 +1,495 @@
 
 #include <yaz/xmalloc.h>
+#include <yaz/log.h>
 #include <isamb.h>
+#include <assert.h>
+
+struct ISAMB_head {
+    int first_block;
+    int last_block;
+    int block_size;
+};
+
+#define ISAMB_DATA_OFFSET 3
 
 struct ISAMB_s {
     BFiles bfs;
+    BFile bf;
     ISAMC_M method;
+    int head_dirty;
+
+    struct ISAMB_head head;
+};
+
+struct ISAMB_block {
+    int pos;
+    int size;
+    int leaf;
+    int dirty;
+    int offset;
+    unsigned char *bytes;
+    void *decodeClientData;
+};
+
+struct ISAMB_PP_s {
+    ISAMB isamb;
+    int level;
+    struct ISAMB_block **block;
 };
 
-typedef unsigned char *Bpage;
+void encode_ptr (char **dst, int pos)
+{
+    memcpy (*dst, &pos, sizeof(pos));
+    (*dst) += sizeof(pos);
+}
 
-ISAMB isamb_open (BFiles bfs, const char *name, ISAMC_M method)
+void decode_ptr (char **src, int *pos)
+{
+    memcpy (pos, *src, sizeof(*pos));
+    (*src) += sizeof(*pos);
+}
+
+ISAMB isamb_open (BFiles bfs, const char *name, int writeflag, ISAMC_M method)
 {
     ISAMB isamb = xmalloc (sizeof(*isamb));
 
     isamb->bfs = bfs;
     isamb->method = (ISAMC_M) xmalloc (sizeof(*method));
     memcpy (isamb->method, method, sizeof(*method));
+
+    isamb->head.first_block = 1;
+    isamb->head.last_block = 1;
+    isamb->head.block_size = 1024;
+    isamb->head_dirty = 0;
+
+    isamb->bf = bf_open (bfs, name, isamb->head.block_size, writeflag);
+    
+    bf_read (isamb->bf, 0, 0, sizeof(struct ISAMB_head),
+             &isamb->head);
     return isamb;
 }
 
 void isamb_close (ISAMB isamb)
 {
+    if (isamb->head_dirty)
+        bf_write (isamb->bf, 0, 0, sizeof(struct ISAMB_head), &isamb->head);
     xfree (isamb->method);
     xfree (isamb);
 }
 
-#if 0
-/* read page at pos */
-void isamb_get_block (ISAMB is, ISAMB_pos pos, Bpage *page)
+struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
 {
+    struct ISAMB_block *p;
+    if (!pos)
+        return 0;
+    p = xmalloc (sizeof(*p));
+    p->pos = pos;
+    p->bytes = xmalloc (b->head.block_size);
+    bf_read (b->bf, pos, 0, 0, p->bytes);
+    p->leaf = p->bytes[0];
+    p->size = p->bytes[1] + 256 * p->bytes[2];
+    p->offset = ISAMB_DATA_OFFSET;
+    p->dirty = 0;
+    p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
+    return p;
 }
 
-/* alloc page */
-ISAMB_pos isamb_alloc_block (ISAMB is, int block_size, Bpage *page)
+struct ISAMB_block *new_block (ISAMB b, int leaf)
 {
+    struct ISAMB_block *p;
+    
+    p = xmalloc (sizeof(*p));
+    p->pos = b->head.last_block++;
+    b->head_dirty = 1;
+    p->bytes = xmalloc (b->head.block_size);
+    memset (p->bytes, 0, b->head.block_size);
+    p->leaf = leaf;
+    p->size = ISAMB_DATA_OFFSET;
+    p->dirty = 1;
+    p->offset = ISAMB_DATA_OFFSET;
+    p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
+    return p;
 }
 
-#define isamb_page_set_leaf (p)   0[p] = 1
-#define isamb_page_set_noleaf (p) 0[p] = 0
-#define isamb_page_datalist (4+p)
-
-static void isamb_page_set_no(Bpage page, int no)
+void close_block (ISAMB b, struct ISAMB_block *p)
 {
-    page[1] = no & 255;
-    page[2] = (no >> 8) & 255;
-    page[3] = (no >> 16) & 255;
+    if (!p)
+        return;
+    if (p->dirty)
+    {
+        p->bytes[0] = p->leaf;
+        p->bytes[1] = p->size & 255;
+        p->bytes[2] = p->size >> 8;
+        bf_write (b->bf, p->pos, 0, 0, p->bytes);
+    }
+    (*b->method->code_stop)(ISAMC_DECODE, p->decodeClientData);
+    xfree (p->bytes);
+    xfree (p);
 }
 
-static int isamb_page_get_no(Bpage page)
+void insert_sub (ISAMB b, struct ISAMB_block *p, const void *new_item,
+                 struct ISAMB_block **sp,
+                 void *sub_item, int *sub_size);
+
+void insert_leaf (ISAMB b, struct ISAMB_block *p, const void *new_item,
+                  struct ISAMB_block **sp,
+                  void *sub_item, int *sub_size)
 {
-    return page[1] + 256*page[2] + 65536*page[3];
+    char dst_buf[2048];
+    char *dst = dst_buf;
+    char *src = p->bytes + ISAMB_DATA_OFFSET;
+    char *endp = p->bytes + p->size;
+    void *c1 = (*b->method->code_start)(ISAMC_DECODE);
+    void *c2 = (*b->method->code_start)(ISAMC_ENCODE);
+    char *half1 = 0;
+    char *half2 = 0;
+    char *cut = dst_buf + p->size / 2;
+    char cut_item_buf[256];
+    int cut_item_size = 0;
+
+    while (src != endp)
+    {
+        char file_item_buf[256];
+        char *file_item = file_item_buf;
+
+        (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
+        if (new_item)
+        {
+            int d = (*b->method->compare_item)(file_item_buf, new_item);
+            if (d > 0)
+            {
+                char *item_ptr = (char*) new_item;
+                (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &item_ptr);
+                new_item = 0;
+                p->dirty = 1;
+            }
+            else if (d == 0)
+            {
+                new_item = 0;
+            }
+        }
+        
+        if (!half1 && dst > cut)   
+        {
+            half1 = dst; /* candidate for splitting */
+
+            file_item = file_item_buf;
+            (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &file_item);
+
+            cut_item_size = file_item - file_item_buf;
+            memcpy (cut_item_buf, file_item_buf, cut_item_size);
+
+            half2 = dst;
+        }
+        else
+        {
+            file_item = file_item_buf;
+            (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &file_item);
+        }
+    }
+    if (new_item)
+    {
+        char *item_ptr = (char*) new_item;
+        (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &item_ptr);
+        new_item = 0;
+        p->dirty = 1;
+    }
+    p->size = dst - dst_buf + ISAMB_DATA_OFFSET;
+    if (p->size > b->head.block_size)
+    {
+        char *first_dst;
+        char *cut_item = cut_item_buf;
+ 
+       /* first half */
+        p->size = half1 - dst_buf + ISAMB_DATA_OFFSET;
+        memcpy (p->bytes+ISAMB_DATA_OFFSET, dst_buf, half1 - dst_buf);
+
+        /* second half */
+        *sp = new_block (b, 1);
+
+        (*b->method->code_reset)(c2);
+
+        first_dst = (*sp)->bytes + ISAMB_DATA_OFFSET;
+
+        (*b->method->code_item)(ISAMC_ENCODE, c2, &first_dst, &cut_item);
+
+        memcpy (first_dst, half2, dst - half2);
+
+        (*sp)->size = (first_dst - (char*) (*sp)->bytes) + (dst - half2);
+        (*sp)->dirty = 1;
+        p->dirty = 1;
+        memcpy (sub_item, cut_item_buf, cut_item_size);
+        *sub_size = cut_item_size;
+
+        yaz_log (LOG_LOG, "l split %d / %d", p->size, (*sp)->size);
+
+    }
+    else
+    {
+        assert (p->size > ISAMB_DATA_OFFSET);
+        assert (p->size <= b->head.block_size);
+        memcpy (p->bytes+ISAMB_DATA_OFFSET, dst_buf, dst - dst_buf);
+        *sp = 0;
+    }
+    (*b->method->code_stop)(ISAMC_DECODE, c1);
+    (*b->method->code_stop)(ISAMC_ENCODE, c2);
 }
 
-void isamb_insert_sub(ISAMB is, ISAMB_pos *pos, const void *data)
+void insert_int (ISAMB b, struct ISAMB_block *p, const void *new_item,
+                 struct ISAMB_block **sp,
+                 void *split_item, int *split_size)
 {
-    const char *src;
-    char dst[200];
-    int no, i;
-    
-    isamb_get_block (is, *pos, &page);
-    if (!isamb_page_isleaf (page))
+    char *startp = p->bytes + ISAMB_DATA_OFFSET;
+    char *src = startp;
+    char *endp = p->bytes + p->size;
+    int pos;
+    struct ISAMB_block *sub_p1 = 0, *sub_p2 = 0;
+    char sub_item[256];
+    int sub_size;
+
+    *sp = 0;
+
+    decode_ptr (&src, &pos);
+    while (src != endp)
+    {
+        int item_len;
+        int d;
+        decode_ptr (&src, &item_len);
+        d = (*b->method->compare_item)(src, new_item);
+        if (d > 0)
+        {
+            sub_p1 = open_block (b, pos);
+            assert (sub_p1);
+            insert_sub (b, sub_p1, new_item, &sub_p2, 
+                        sub_item, &sub_size);
+            break;
+        }
+        src += item_len;
+        decode_ptr (&src, &pos);
+    }
+    if (!sub_p1)
     {
-	ISAMB_pos subptr;
-	src = isamb_page_datalist (page);
-	no = isamb_page_get_no (page);
-	decodeClientData = (*is->method->code_start)(ISAMC_DECODE);
-	
-	isamb_read_subptr (&subptr, &src);
-	for (i = 0; i<no; i++)
-	{
-	    const char *src0 = src;
-	    
-	    (*is->method->code_item)(ISAMC_DECODE, decodeClientData,
-				     dst, &src);
-	    if ((*is->method->compare_item)(data, dst) < 0)
-		break;
-	    
-	    isamb_read_subptr (&subptr, src);
-	}
-	isamb_insert_sub (is, subptr, data);
-	*pos = subptr;
-	(*is->method->code_stop)(ISAMC_DECODE, decodeClientData);
+        sub_p1 = open_block (b, pos);
+        assert (sub_p1);
+        insert_sub (b, sub_p1, new_item, &sub_p2, 
+                    sub_item, &sub_size);
     }
+    if (sub_p2)
+    {
+        char dst_buf[2048];
+        char *dst = dst_buf;
+
+        assert (sub_size < 20);
+
+        memcpy (dst, startp, src - startp);
+                
+        dst += src - startp;
+
+        encode_ptr (&dst, sub_size);      /* sub length and item */
+        memcpy (dst, sub_item, sub_size);
+        dst += sub_size;
+
+        encode_ptr (&dst, sub_p2->pos);   /* pos */
+
+        if (endp - src)                   /* remaining data */
+        {
+            memcpy (dst, src, endp - src);
+            dst += endp - src;
+        }
+        p->size = dst - dst_buf + ISAMB_DATA_OFFSET;
+        if (p->size <= b->head.block_size)
+        {
+            memcpy (startp, dst_buf, dst - dst_buf);
+        }
+        else
+        {
+            int p_new_size;
+            char *half;
+            src = dst_buf;
+            endp = dst;
+
+            half = src + b->head.block_size/2;
+            decode_ptr (&src, &pos);
+            while (src <= half)
+            {
+                decode_ptr (&src, split_size);
+                src += *split_size;
+                decode_ptr (&src, &pos);
+            }
+            p_new_size = src - dst_buf;
+            memcpy (p->bytes + ISAMB_DATA_OFFSET, dst_buf, p_new_size);
+            p_new_size += ISAMB_DATA_OFFSET;
+
+            decode_ptr (&src, split_size);
+            memcpy (split_item, src, *split_size);
+            src += *split_size;
+
+            *sp = new_block (b, 0);
+            (*sp)->size = endp - src;
+            memcpy ((*sp)->bytes+ISAMB_DATA_OFFSET, src, (*sp)->size);
+            (*sp)->size += ISAMB_DATA_OFFSET;
+
+            yaz_log (LOG_LOG, "i split %d -> %d %d",
+                     p->size, p_new_size, (*sp)->size);
+            p->size = p_new_size;
+        }
+        p->dirty = 1;
+        close_block (b, sub_p2);
+    }
+    close_block (b, sub_p1);
+}
+
+void insert_sub (ISAMB b, struct ISAMB_block *p, const void *new_item,
+                struct ISAMB_block **sp,
+                void *sub_item, int *sub_size)
+{
+    if (p->leaf)
+        insert_leaf (b, p, new_item, sp, sub_item, sub_size);
+    else
+        insert_int (b, p, new_item, sp, sub_item, sub_size);
+}
+
+int isamb_insert_one (ISAMB b, const void *item, ISAMC_P pos)
+{
+    struct ISAMB_block *p, *sp = 0;
+    char sub_item[256];
+    int sub_size;
+
+    if (!pos)
+        p = new_block (b, 1);
     else
+        p = open_block (b, pos);
+    if (!p)
+        return -1;
+
+    insert_sub (b, p, item, &sp, sub_item, &sub_size);
+    if (sp)
+    {    /* increase level of tree by one */
+        struct ISAMB_block *p2 = new_block (b, 0);
+        char *dst = p2->bytes + p2->size;
+        
+        encode_ptr (&dst, p->pos);
+        assert (sub_size < 20);
+        encode_ptr (&dst, sub_size);
+        memcpy (dst, sub_item, sub_size);
+        dst += sub_size;
+        encode_ptr (&dst, sp->pos);
+
+        p2->size = dst - (char*) p2->bytes;
+        pos = p2->pos;  /* return new super page */
+        close_block (b, sp);
+        close_block (b, p2);
+    }
+    else
+        pos = p->pos;   /* return current one (again) */
+    close_block (b, p);
+    return pos;
+}
+
+ISAMB_P isamb_merge (ISAMB b, ISAMB_P pos, ISAMC_I data)
+{
+    int i_mode;
+    char item_buf[256];
+    char *item_ptr = item_buf;
+    while ((*data->read_item)(data->clientData, &item_ptr, &i_mode))
     {
-	src = isamb_page_datalist (page);
-	no = isamb_page_get_no (page);
-	decodeClientData = (*is->method->code_start)(ISAMC_DECODE);
-	diff = -1;
-	for (i = 0; i<no; i++)
-	{
-	    int diff;
-	    (*is->method->code_item)(ISAMC_DECODE, decodeClientData,
-				     dst, &src);
-	    diff = (*is->method->compare_item)(data, dst);
-	    if (diff <= 0)
-		break;
-	}
-	if (diff < 0)
-	{
-	    int j;
-	    src = isamb_page_datalist (page);
-	    page2 = isamb_page_dup (is, page);
-	    dst2 = isamb_page_datalist (page2);
-	    src2 = data;
-	    for (j = 0; j <= no; j++)
-	    {
-		if ( i == j)
-		    (*is->method->code_item)(ISAMC_ENCODE, encodeClientData,
-					     &dst2, &src2);
-		if (j < no)
-		{
-		    char *dst0 = dst;
-		    (*is->method->code_item)(ISAMC_DECODE, decodeClientData,
-					     &dst, &src);
-		    (*is->method->code_item)(ISAMC_ENCODE, encodeClientData,
-					     &dst2, &dst0);
-		}
-	    }
-	}
+        item_ptr = item_buf;
+        pos = isamb_insert_one (b, item_buf, pos);
     }
+    return pos;
 }
-/* insert data(input) in table is(input) at pos(input/output) */
-int isamb_insert (ISAMB is, ISAMB_pos *pos, const void *data)
+
+ISAMB_PP isamb_pp_open (ISAMB isamb, ISAMB_P pos)
 {
-    void *decodeClientData;
+    ISAMB_PP pp = xmalloc (sizeof(*pp));
 
-    Bpage page;
-    if (*pos == 0)
+    pp->isamb = isamb;
+    pp->block = xmalloc (10 * sizeof(*pp->block));
+
+    pp->level = 0;
+    while (1)
     {
-	*pos = isamb_alloc_block (is, 1024, &page);
-	isamb_page_set_leaf (page);
-	isamb_page_set_no (page, 0);
+        struct ISAMB_block *p = open_block (isamb, pos);
+        char *src = p->bytes + p->offset;
+        pp->block[pp->level] = p;
+
+        if (p->bytes[0]) /* leaf */
+            break;
+
+        decode_ptr (&src, &pos);
+        p->offset = src - (char*) p->bytes;
+        pp->level++;
     }
-    else     /* find leaf ... */
+    pp->block[pp->level+1] = 0;
+    return pp;
+}
+
+void isamb_pp_close (ISAMB_PP pp)
+{
+    int i;
+    if (!pp)
+        return;
+    for (i = 0; i <= pp->level; i++)
+        close_block (pp->isamb, pp->block[i]);
+    xfree (pp->block);
+    xfree (pp);
+}
+
+int isamb_pp_read (ISAMB_PP pp, void *buf)
+{
+    char *dst = buf;
+    char *src;
+    struct ISAMB_block *p = pp->block[pp->level];
+    if (!p)
+        return 0;
+
+    while (p->offset == p->size)
     {
-	isamb_insert_sub (is, pos, const void *data);
+        int pos, item_len;
+        while (p->offset == p->size)
+        {
+            if (pp->level == 0)
+                return 0;
+            close_block (pp->isamb, pp->block[pp->level]);
+            pp->block[pp->level] = 0;
+            (pp->level)--;
+            p = pp->block[pp->level];
+            assert (p->bytes[0] == 0);  /* must be int */
+        }
+        src = p->bytes + p->offset;
+        
+        decode_ptr (&src, &item_len);
+        src += item_len;
+        decode_ptr (&src, &pos);
+        
+        p->offset = src - (char*) p->bytes;
 
+        ++(pp->level);
+        
+        while (1)
+        {
+            pp->block[pp->level] = p = open_block (pp->isamb, pos);
+            
+            if (p->bytes[0]) /* leaf */
+            {
+                break;
+            }
+            src = p->bytes + p->offset;
+            decode_ptr (&src, &pos);
+            p->offset = src - (char*) p->bytes;
+            pp->level++;
+        }
     }
+    assert (p->offset < p->size);
+    assert (p->bytes[0]);
+    src = p->bytes + p->offset;
+    (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
+                                    &dst, &src);
+    p->offset = src - (char*) p->bytes;
+    return 1;
+}
+
+int isamb_pp_num (ISAMB_PP pp)
+{
+    return 1;
 }
-#endif