X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Fsorter%2Fsorter.h;h=da848979da595369c5e6b10e29e73bc287b3fbf4;hb=5c21b096ab39ece4c9ad80047144b2fde0c54758;hp=24c6de190479bd71e841171abdc45380191fd8ff;hpb=3d85e302b6754446d75daad8e333cc53859db05b;p=libucw.git

diff --git a/lib/sorter/sorter.h b/lib/sorter/sorter.h
index 24c6de19..da848979 100644
--- a/lib/sorter/sorter.h
+++ b/lib/sorter/sorter.h
@@ -14,19 +14,26 @@
  *  corresponding preprocessor macros, it generates a file sorter
  *  with the parameters given.
  *
- *  FIXME: explain the basics (keys and data, callbacks etc.)
+ *  The sorter operates on fastbufs containing sequences of items. Each items
+ *  consists of a key, optionally followed by data. The keys are represented
+ *  by fixed-size structures of type SORT_KEY internally, if this format differs
+ *  from the on-disk format, explicit reading and writing routines can be provided.
+ *  The data are always copied verbatim, unless the sorter is in the merging
+ *  mode in which it calls callbacks for merging of items with equal keys.
+ *
+ *  All callbacks must be thread-safe.
  *
  *  Basic parameters and callbacks:
  *
- *  SORT_PREFIX(x)      add a name prefix (used on all global names
- *			defined by the sorter)
+ *  SORT_PREFIX(x)      add a name prefix (used on all global names defined by the sorter)
  *
- *  SORT_KEY		data type capable of storing a single key.
+ *  SORT_KEY		data type capable of holding a single key in memory (the on-disk
+ *			representation can be different). Alternatively, you can use:
  *  SORT_KEY_REGULAR	data type holding a single key both in memory and on disk;
  *			in this case, bread() and bwrite() is used to read/write keys
  *			and it's also assumed that the keys are not very long.
  *  int PREFIX_compare(SORT_KEY *a, SORT_KEY *b)
- *			compares two keys, result like strcmp(). Mandatory.
+ *			compares two keys, returns result like strcmp(). Mandatory.
  *  int PREFIX_read_key(struct fastbuf *f, SORT_KEY *k)
  *			reads a key from a fastbuf, returns nonzero=ok, 0=EOF.
  *			Mandatory unless SORT_KEY_REGULAR is defined.
@@ -42,78 +49,272 @@
  *
  *  Integer sorting:
  *
- *  SORT_INT(key)	We are sorting by an integer value. In this mode, PREFIX_compare
- *			is supplied automatically and the sorting function gets an extra
- *			parameter specifying a range of the integers. The better the range
- *			fits, the faster we sort. Sets up SORT_HASH_xxx automatically.
+ *  SORT_INT(key)	we are sorting by an integer value returned by this macro.
+ *			In this mode, PREFIX_compare is supplied automatically and the sorting
+ *			function gets an extra parameter specifying the range of the integers.
+ *			The better the range fits, the faster we sort.
+ *			Sets up SORT_HASH_xxx automatically.
+ *  SORT_INT64(key)	the same for 64-bit integers.
  *
  *  Hashing (optional, but it can speed sorting up):
  *
- *  SORT_HASH_FN(key)	returns a monotone hash of a given key. Monotone hash is a function f
- *			such that f(x) < f(y) implies x < y and which is approximately uniformly
- *			distributed.
- *  SORT_HASH_BITS	how many bits do the hashes have.
+ *  SORT_HASH_BITS	signals that a monotone hashing function returning a given number of
+ *			bits is available. A monotone hash is a function f from keys to integers
+ *			such that f(x) < f(y) implies x < y, which is approximately uniformly
+ *			distributed. It should be declared as:
+ *  uns PREFIX_hash(SORT_KEY *a)
  *
  *  Unification:
  *
- *  SORT_MERGE		merge items with identical keys, needs the following functions:
- *  void PREFIX_write_merged(struct fastbuf *f, SORT_KEY **keys, uns n, byte *buf)
+ *  SORT_UNIFY		merge items with identical keys. It requires the following functions:
+ *  void PREFIX_write_merged(struct fastbuf *f, SORT_KEY **keys, void **data, uns n, void *buf)
  *			takes n records in memory with keys which compare equal and writes
- *			a single record to the given fastbuf. Data for each key can
- *			be accessed by the SORT_GET_DATA(*key) macro. `buf' points
- *			to a buffer which is guaranteed to hold all given records.
+ *			a single record to the given fastbuf. `buf' points to a buffer which
+ *			is guaranteed to hold the sum of workspace requirements (see below)
+ *			over all given records. The function is allowed to modify all its inputs.
  *  void PREFIX_copy_merged(SORT_KEY **keys, struct fastbuf **data, uns n, struct fastbuf *dest)
  *			takes n records with keys in memory and data in fastbufs and writes
- *			a single record.
+ *			a single record. Used only if SORT_DATA_SIZE or SORT_UNIFY_WORKSPACE
+ *			is defined.
+ *  SORT_UNIFY_WORKSPACE(key)
+ *			gets a key and returns the amount of workspace required when merging
+ *			the given record. Defaults to 0.
  *
  *  Input (choose one of these):
  *
  *  SORT_INPUT_FILE	file of a given name
- *  SORT_INPUT_FB	fastbuf stream
- *  SORT_INPUT_PRESORT	custom presorter: call function PREFIX_presorter (see below)
- *			to get successive batches of pre-sorted data as temporary
- *			fastbuf streams or NULL if no more data is available.
+ *  SORT_INPUT_FB	seekable fastbuf stream
+ *  SORT_INPUT_PIPE	non-seekable fastbuf stream
+ *  SORT_INPUT_PRESORT	custom presorter. Calls function
+ *  int PREFIX_presort(struct fastbuf *dest, void *buf, size_t bufsize)
+ *			to get successive batches of pre-sorted data.
  *			The function is passed a page-aligned presorting buffer.
+ *			It returns 1 on success or 0 on EOF.
+ *  SORT_DELETE_INPUT	A C expression, if true, then the input files are deleted
+ *			as soon as possible.
  *
  *  Output (chose one of these):
  *
  *  SORT_OUTPUT_FILE	file of a given name
  *  SORT_OUTPUT_FB	temporary fastbuf stream
- *  SORT_OUTPUT_THIS_FB	a given fastbuf stream which can already contain a header
+ *  SORT_OUTPUT_THIS_FB	a given fastbuf stream which can already contain some data
+ *
+ *  Other switches:
  *
- *  FIXME: Maybe implement these:
- *  ??? SORT_UNIQUE		all items have distinct keys (checked in debug mode)
- *  ??? SORT_DELETE_INPUT	a C expression, if true, the input files are
- *			deleted as soon as possible
- *  ??? SORT_ALIGNED
+ *  SORT_UNIQUE		all items have distinct keys (checked in debug mode)
  *
  *  The function generated:
  *
- *  <outfb> PREFIX_SORT(<in>, <out>, <range>), where:
- *			<in> = input file name/fastbuf
- *			<out> = output file name/fastbuf
+ *  <outfb> PREFIX_sort(<in>, <out> [,<range>]), where:
+ *			<in> = input file name/fastbuf or NULL
+ *			<out> = output file name/fastbuf or NULL
  *			<range> = maximum integer value for the SORT_INT mode
- *			<outfb> = output fastbuf (in SORT_OUTPUT_FB mode)
- *			(any parameter can be missing if it is not applicable).
- *
- *  void PREFIX_merge_data(struct fastbuf *src1, *src2, *dest, SORT_KEY *k1, *k2)
- *			[used only in case SORT_UNIFY is defined]
- *			write just fetched key k to dest and merge data from
- *			two records with the same key (k1 and k2 are key occurences
- *			in the corresponding streams).
- *  SORT_KEY * PREFIX_merge_items(SORT_KEY *a, SORT_KEY *b)
- *			[used only with SORT_PRESORT && SORT_UNIFY]
- *			merge two items with the same key, returns pointer
- *			to at most one of the items, the rest will be removed
- *			from the list of items, but not deallocated, so
- *			the remaining item can freely reference data of the
- *			other one.
  *
  *  After including this file, all parameter macros are automatically
  *  undef'd.
  */
 
+#include "lib/sorter/common.h"
+#include "lib/fastbuf.h"
+
+#include <fcntl.h>
+
 #define P(x) SORT_PREFIX(x)
 
+#ifdef SORT_KEY_REGULAR
+typedef SORT_KEY_REGULAR P(key);
+static inline int P(read_key) (struct fastbuf *f, P(key) *k)
+{
+  return breadb(f, k, sizeof(P(key)));
+}
+static inline void P(write_key) (struct fastbuf *f, P(key) *k)
+{
+  bwrite(f, k, sizeof(P(key)));
+}
+#elif defined(SORT_KEY)
+typedef SORT_KEY P(key);
+#else
+#error Missing definition of sorting key.
+#endif
+
+#ifdef SORT_INT64
+typedef u64 P(hash_t);
+#define SORT_INT SORT_INT64
+#define SORT_LONG_HASH
+#else
+typedef uns P(hash_t);
+#endif
+
+#ifdef SORT_INT
+static inline int P(compare) (P(key) *x, P(key) *y)
+{
+  if (SORT_INT(*x) < SORT_INT(*y))
+    return -1;
+  if (SORT_INT(*x) > SORT_INT(*y))
+    return 1;
+  return 0;
+}
+
+#ifndef SORT_HASH_BITS
+static inline P(hash_t) P(hash) (P(key) *x)
+{
+  return SORT_INT((*x));
+}
+#endif
+#endif
+
+#ifdef SORT_UNIFY
+#define LESS <
+#else
+#define LESS <=
+#endif
+#define SWAP(x,y,z) do { z=x; x=y; y=z; } while(0)
+
+#if defined(SORT_UNIQUE) && defined(DEBUG_ASSERTS)
+#define SORT_ASSERT_UNIQUE
+#endif
+
+#ifdef SORT_KEY_SIZE
+#define SORT_VAR_KEY
+#else
+#define SORT_KEY_SIZE(key) sizeof(key)
+#endif
+
+#ifdef SORT_DATA_SIZE
+#define SORT_VAR_DATA
+#else
+#define SORT_DATA_SIZE(key) 0
+#endif
+
+static inline void P(copy_data)(P(key) *key, struct fastbuf *in, struct fastbuf *out)
+{
+  P(write_key)(out, key);
+#ifdef SORT_VAR_DATA
+  bbcopy(in, out, SORT_DATA_SIZE(*key));
+#else
+  (void) in;
+#endif
+}
+
+#if defined(SORT_UNIFY) && !defined(SORT_VAR_DATA) && !defined(SORT_UNIFY_WORKSPACE)
+static inline void P(copy_merged)(P(key) **keys, struct fastbuf **data UNUSED, uns n, struct fastbuf *dest)
+{
+  P(write_merged)(dest, keys, NULL, n, NULL);
+}
+#endif
+
+#if defined(SORT_HASH_BITS) || defined(SORT_INT)
+#define SORT_INTERNAL_RADIX
+#include "lib/sorter/s-radix.h"
+#endif
+
+#if defined(SORT_VAR_KEY) || defined(SORT_VAR_DATA) || defined(SORT_UNIFY_WORKSPACE)
+#include "lib/sorter/s-internal.h"
+#else
+#include "lib/sorter/s-fixint.h"
+#endif
+
+#include "lib/sorter/s-twoway.h"
+#include "lib/sorter/s-multiway.h"
+
+static struct fastbuf *P(sort)(
+#ifdef SORT_INPUT_FILE
+			       byte *in,
+#else
+			       struct fastbuf *in,
+#endif
+#ifdef SORT_OUTPUT_FILE
+			       byte *out
+#else
+			       struct fastbuf *out
+#endif
+#ifdef SORT_INT
+			       , u64 int_range
+#endif
+			       )
+{
+  struct sort_context ctx;
+  bzero(&ctx, sizeof(ctx));
+
+#ifdef SORT_INPUT_FILE
+  ctx.in_fb = bopen_file(in, O_RDONLY, &sorter_fb_params);
+  ctx.in_size = bfilesize(ctx.in_fb);
+#elif defined(SORT_INPUT_FB)
+  ctx.in_fb = in;
+  ctx.in_size = bfilesize(in);
+#elif defined(SORT_INPUT_PIPE)
+  ctx.in_fb = in;
+  ctx.in_size = ~(u64)0;
+#elif defined(SORT_INPUT_PRESORT)
+  ASSERT(!in);
+  ctx.custom_presort = P(presort);
+  ctx.in_size = ~(u64)0;
+#else
+#error No input given.
+#endif
+#ifdef SORT_DELETE_INPUT
+  if (SORT_DELETE_INPUT)
+    bconfig(ctx.in_fb, BCONFIG_IS_TEMP_FILE, 1);
+#endif
+
+#ifdef SORT_OUTPUT_FB
+  ASSERT(!out);
+#elif defined(SORT_OUTPUT_THIS_FB)
+  ctx.out_fb = out;
+#elif defined(SORT_OUTPUT_FILE)
+  /* Just assume fastbuf output and rename the fastbuf later */
+#else
+#error No output given.
+#endif
+
+#ifdef SORT_HASH_BITS
+  ctx.hash_bits = SORT_HASH_BITS;
+  ctx.radix_split = P(radix_split);
+#elif defined(SORT_INT)
+  ctx.hash_bits = 0;
+  while (ctx.hash_bits < 64 && (int_range >> ctx.hash_bits))
+    ctx.hash_bits++;
+  ctx.radix_split = P(radix_split);
+#endif
+
+  ctx.internal_sort = P(internal);
+  ctx.internal_estimate = P(internal_estimate);
+  ctx.twoway_merge = P(twoway_merge);
+  ctx.multiway_merge = P(multiway_merge);
+
+  sorter_run(&ctx);
+
+#ifdef SORT_OUTPUT_FILE
+  bfix_tmp_file(ctx.out_fb, out);
+  ctx.out_fb = NULL;
+#endif
+  return ctx.out_fb;
+}
+
+#undef SORT_ASSERT_UNIQUE
+#undef SORT_DATA_SIZE
+#undef SORT_DELETE_INPUT
+#undef SORT_HASH_BITS
+#undef SORT_INPUT_FB
+#undef SORT_INPUT_FILE
+#undef SORT_INPUT_PIPE
+#undef SORT_INPUT_PRESORT
+#undef SORT_INT
+#undef SORT_INT64
+#undef SORT_INTERNAL_RADIX
+#undef SORT_KEY
+#undef SORT_KEY_REGULAR
+#undef SORT_KEY_SIZE
+#undef SORT_LONG_HASH
+#undef SORT_OUTPUT_FB
+#undef SORT_OUTPUT_FILE
+#undef SORT_OUTPUT_THIS_FB
+#undef SORT_PREFIX
+#undef SORT_UNIFY
+#undef SORT_UNIFY_WORKSPACE
+#undef SORT_UNIQUE
+#undef SORT_VAR_DATA
+#undef SORT_VAR_KEY
+#undef SWAP
+#undef LESS
 #undef P
-/* FIXME: Check that we undef everything we should. */