2 * UCW Library -- Universal Sorter: Governing Routines
4 * (c) 2007 Martin Mares <mj@ucw.cz>
6 * This software may be freely distributed and used according to the terms
7 * of the GNU Lesser General Public License.
11 #include "lib/fastbuf.h"
12 #include "lib/mempool.h"
13 #include "lib/sorter/common.h"
17 static int sorter_presort(struct sort_context *ctx, struct sort_bucket *in, struct sort_bucket *out, struct sort_bucket *out_only)
19 sorter_alloc_buf(ctx);
20 if (in->flags & SBF_CUSTOM_PRESORT)
22 struct fastbuf *f = sbuck_write(out);
23 return ctx->custom_presort(f, ctx->big_buf, ctx->big_buf_size); // FIXME: out_only optimization?
25 return ctx->internal_sort(ctx, in, out, out_only);
28 static inline struct sort_bucket *
29 sbuck_join_to(struct sort_bucket *b)
31 if (sorter_debug & SORT_DEBUG_NO_JOIN)
34 struct sort_bucket *out = (struct sort_bucket *) b->n.prev; // Such bucket is guaranteed to exist
35 return (out->flags & SBF_FINAL) ? out : NULL;
39 sorter_join(struct sort_bucket *b)
41 struct sort_bucket *join = (struct sort_bucket *) b->n.prev;
42 ASSERT(join->flags & SBF_FINAL);
45 if (!sbuck_has_file(join))
47 // The final bucket doesn't have any file associated yet, so replace
48 // it with the new bucket.
49 SORT_XTRACE("Replaced final bucket");
50 b->flags |= SBF_FINAL;
55 SORT_TRACE("Copying %jd bytes to output file", (uintmax_t) sbuck_size(b));
56 struct fastbuf *src = sbuck_read(b);
57 struct fastbuf *dest = sbuck_write(join);
58 bbcopy(src, dest, ~0U);
64 sorter_twoway(struct sort_context *ctx, struct sort_bucket *b)
66 struct sort_bucket *ins[3] = { NULL }, *outs[3] = { NULL };
67 cnode *list_pos = b->n.prev;
68 struct sort_bucket *join = sbuck_join_to(b);
70 if (!(sorter_debug & SORT_DEBUG_NO_PRESORT) || (b->flags & SBF_CUSTOM_PRESORT))
72 SORT_TRACE("Presorting");
73 ins[0] = sbuck_new(ctx);
74 if (!sorter_presort(ctx, b, ins[0], join ? : ins[0]))
76 SORT_XTRACE("Sorted in memory");
80 clist_insert_after(&ins[0]->n, list_pos);
85 ins[1] = sbuck_new(ctx);
87 while (sorter_presort(ctx, b, ins[i], ins[i]))
93 SORT_TRACE("Skipped presorting");
97 SORT_TRACE("Main sorting");
99 if (ins[0]->runs == 1 && ins[1]->runs == 1 && join)
101 // This is guaranteed to produce a single run, so join if possible
104 ctx->twoway_merge(ctx, ins, outs);
105 ASSERT(outs[0]->runs == 2);
107 SORT_TRACE("Pass done (joined final run)");
112 outs[0] = sbuck_new(ctx);
113 outs[1] = sbuck_new(ctx);
115 ctx->twoway_merge(ctx, ins, outs);
116 SORT_TRACE("Pass done (%d+%d runs, %jd+%jd bytes)", outs[0]->runs, outs[1]->runs, (uintmax_t) sbuck_size(outs[0]), (uintmax_t) sbuck_size(outs[1]));
119 memcpy(ins, outs, 3*sizeof(struct sort_bucket *));
120 } while (sbuck_have(ins[1]));
123 clist_insert_after(&ins[0]->n, list_pos);
127 sorter_run(struct sort_context *ctx)
129 ctx->pool = mp_new(4096);
130 clist_init(&ctx->bucket_list);
132 /* FIXME: There should be a way how to detect size of the input file */
133 /* FIXME: Remember to test sorting of empty files */
135 // Create bucket containing the source
136 struct sort_bucket *bin = sbuck_new(ctx);
137 bin->flags = SBF_SOURCE | SBF_OPEN_READ;
138 if (ctx->custom_presort)
139 bin->flags |= SBF_CUSTOM_PRESORT;
141 bin->fb = ctx->in_fb;
144 bin->hash_bits = ctx->hash_bits;
145 clist_add_tail(&ctx->bucket_list, &bin->n);
147 // Create bucket for the output
148 struct sort_bucket *bout = sbuck_new(ctx);
149 bout->flags = SBF_FINAL;
150 bout->fb = ctx->out_fb;
153 clist_add_head(&ctx->bucket_list, &bout->n);
155 struct sort_bucket *b;
156 while (bout = clist_head(&ctx->bucket_list), b = clist_next(&ctx->bucket_list, &bout->n))
160 else if (b->runs == 1)
163 sorter_twoway(ctx, b);
166 sorter_free_buf(ctx);
167 sbuck_write(bout); // Force empty bucket to a file
168 SORT_XTRACE("Final size: %jd", (uintmax_t) sbuck_size(bout));
169 ctx->out_fb = sbuck_read(bout);