/* * contrib/tablefunc/tablefunc.c * * * tablefunc * * Sample to demonstrate C functions which return setof scalar * and setof composite. * Joe Conway * And contributors: * Nabil Sayegh * * Copyright (c) 2002-2020, PostgreSQL Global Development Group * * Permission to use, copy, modify, and distribute this software and its * documentation for any purpose, without fee, and without a written agreement * is hereby granted, provided that the above copyright notice and this * paragraph and the following two paragraphs appear in all copies. * * IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. * */ #include "postgres.h" #include #include "access/htup_details.h" #include "catalog/pg_type.h" #include "executor/spi.h" #include "funcapi.h" #include "lib/stringinfo.h" #include "miscadmin.h" #include "tablefunc.h" #include "utils/builtins.h" PG_MODULE_MAGIC; static HTAB *load_categories_hash(char *cats_sql, MemoryContext per_query_ctx); static Tuplestorestate *get_crosstab_tuplestore(char *sql, HTAB *crosstab_hash, TupleDesc tupdesc, MemoryContext per_query_ctx, bool randomAccess); static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool show_serial); static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2); static void compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2); static void get_normal_pair(float8 *x1, float8 *x2); static Tuplestorestate *connectby(char *relname, char *key_fld, char *parent_key_fld, char *orderby_fld, char *branch_delim, char *start_with, int max_depth, bool show_branch, bool show_serial, MemoryContext per_query_ctx, bool randomAccess, AttInMetadata *attinmeta); static void build_tuplestore_recursively(char *key_fld, char *parent_key_fld, char *relname, char *orderby_fld, char *branch_delim, char *start_with, char *branch, int level, int *serial, int max_depth, bool show_branch, bool show_serial, MemoryContext per_query_ctx, AttInMetadata *attinmeta, Tuplestorestate *tupstore); typedef struct { float8 mean; /* mean of the distribution */ float8 stddev; /* stddev of the distribution */ float8 carry_val; /* hold second generated value */ bool use_carry; /* use second generated value */ } normal_rand_fctx; #define xpfree(var_) \ do { \ if (var_ != NULL) \ { \ pfree(var_); \ var_ = NULL; \ } \ } while (0) #define xpstrdup(tgtvar_, srcvar_) \ do { \ if (srcvar_) \ tgtvar_ = pstrdup(srcvar_); \ else \ tgtvar_ = NULL; \ } while (0) #define xstreq(tgtvar_, srcvar_) \ (((tgtvar_ == NULL) && (srcvar_ == NULL)) || \ ((tgtvar_ != NULL) && (srcvar_ != NULL) && (strcmp(tgtvar_, srcvar_) == 0))) /* sign, 10 digits, '\0' */ #define INT32_STRLEN 12 /* stored info for a crosstab category */ typedef struct crosstab_cat_desc { char *catname; /* full category name */ uint64 attidx; /* zero based */ } crosstab_cat_desc; #define MAX_CATNAME_LEN NAMEDATALEN #define INIT_CATS 64 #define crosstab_HashTableLookup(HASHTAB, CATNAME, CATDESC) \ do { \ crosstab_HashEnt *hentry; char key[MAX_CATNAME_LEN]; \ \ MemSet(key, 0, MAX_CATNAME_LEN); \ snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATNAME); \ hentry = (crosstab_HashEnt*) hash_search(HASHTAB, \ key, HASH_FIND, NULL); \ if (hentry) \ CATDESC = hentry->catdesc; \ else \ CATDESC = NULL; \ } while(0) #define crosstab_HashTableInsert(HASHTAB, CATDESC) \ do { \ crosstab_HashEnt *hentry; bool found; char key[MAX_CATNAME_LEN]; \ \ MemSet(key, 0, MAX_CATNAME_LEN); \ snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATDESC->catname); \ hentry = (crosstab_HashEnt*) hash_search(HASHTAB, \ key, HASH_ENTER, &found); \ if (found) \ ereport(ERROR, \ (errcode(ERRCODE_DUPLICATE_OBJECT), \ errmsg("duplicate category name"))); \ hentry->catdesc = CATDESC; \ } while(0) /* hash table */ typedef struct crosstab_hashent { char internal_catname[MAX_CATNAME_LEN]; crosstab_cat_desc *catdesc; } crosstab_HashEnt; /* * normal_rand - return requested number of random values * with a Gaussian (Normal) distribution. * * inputs are int numvals, float8 mean, and float8 stddev * returns setof float8 */ PG_FUNCTION_INFO_V1(normal_rand); Datum normal_rand(PG_FUNCTION_ARGS) { FuncCallContext *funcctx; uint64 call_cntr; uint64 max_calls; normal_rand_fctx *fctx; float8 mean; float8 stddev; float8 carry_val; bool use_carry; MemoryContext oldcontext; /* stuff done only on the first call of the function */ if (SRF_IS_FIRSTCALL()) { /* create a function context for cross-call persistence */ funcctx = SRF_FIRSTCALL_INIT(); /* * switch to memory context appropriate for multiple function calls */ oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx); /* total number of tuples to be returned */ funcctx->max_calls = PG_GETARG_UINT32(0); /* allocate memory for user context */ fctx = (normal_rand_fctx *) palloc(sizeof(normal_rand_fctx)); /* * Use fctx to keep track of upper and lower bounds from call to call. * It will also be used to carry over the spare value we get from the * Box-Muller algorithm so that we only actually calculate a new value * every other call. */ fctx->mean = PG_GETARG_FLOAT8(1); fctx->stddev = PG_GETARG_FLOAT8(2); fctx->carry_val = 0; fctx->use_carry = false; funcctx->user_fctx = fctx; MemoryContextSwitchTo(oldcontext); } /* stuff done on every call of the function */ funcctx = SRF_PERCALL_SETUP(); call_cntr = funcctx->call_cntr; max_calls = funcctx->max_calls; fctx = funcctx->user_fctx; mean = fctx->mean; stddev = fctx->stddev; carry_val = fctx->carry_val; use_carry = fctx->use_carry; if (call_cntr < max_calls) /* do when there is more left to send */ { float8 result; if (use_carry) { /* * reset use_carry and use second value obtained on last pass */ fctx->use_carry = false; result = carry_val; } else { float8 normval_1; float8 normval_2; /* Get the next two normal values */ get_normal_pair(&normval_1, &normval_2); /* use the first */ result = mean + (stddev * normval_1); /* and save the second */ fctx->carry_val = mean + (stddev * normval_2); fctx->use_carry = true; } /* send the result */ SRF_RETURN_NEXT(funcctx, Float8GetDatum(result)); } else /* do when there is no more left */ SRF_RETURN_DONE(funcctx); } /* * get_normal_pair() * Assigns normally distributed (Gaussian) values to a pair of provided * parameters, with mean 0, standard deviation 1. * * This routine implements Algorithm P (Polar method for normal deviates) * from Knuth's _The_Art_of_Computer_Programming_, Volume 2, 3rd ed., pages * 122-126. Knuth cites his source as "The polar method", G. E. P. Box, M. E. * Muller, and G. Marsaglia, _Annals_Math,_Stat._ 29 (1958), 610-611. * */ static void get_normal_pair(float8 *x1, float8 *x2) { float8 u1, u2, v1, v2, s; do { u1 = (float8) random() / (float8) MAX_RANDOM_VALUE; u2 = (float8) random() / (float8) MAX_RANDOM_VALUE; v1 = (2.0 * u1) - 1.0; v2 = (2.0 * u2) - 1.0; s = v1 * v1 + v2 * v2; } while (s >= 1.0); if (s == 0) { *x1 = 0; *x2 = 0; } else { s = sqrt((-2.0 * log(s)) / s); *x1 = v1 * s; *x2 = v2 * s; } } /* * crosstab - create a crosstab of rowids and values columns from a * SQL statement returning one rowid column, one category column, * and one value column. * * e.g. given sql which produces: * * rowid cat value * ------+-------+------- * row1 cat1 val1 * row1 cat2 val2 * row1 cat3 val3 * row1 cat4 val4 * row2 cat1 val5 * row2 cat2 val6 * row2 cat3 val7 * row2 cat4 val8 * * crosstab returns: * <===== values columns =====> * rowid cat1 cat2 cat3 cat4 * ------+-------+-------+-------+------- * row1 val1 val2 val3 val4 * row2 val5 val6 val7 val8 * * NOTES: * 1. SQL result must be ordered by 1,2. * 2. The number of values columns depends on the tuple description * of the function's declared return type. The return type's columns * must match the datatypes of the SQL query's result. The datatype * of the category column can be anything, however. * 3. Missing values (i.e. not enough adjacent rows of same rowid to * fill the number of result values columns) are filled in with nulls. * 4. Extra values (i.e. too many adjacent rows of same rowid to fill * the number of result values columns) are skipped. * 5. Rows with all nulls in the values columns are skipped. */ PG_FUNCTION_INFO_V1(crosstab); Datum crosstab(PG_FUNCTION_ARGS) { char *sql = text_to_cstring(PG_GETARG_TEXT_PP(0)); ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; Tuplestorestate *tupstore; TupleDesc tupdesc; uint64 call_cntr; uint64 max_calls; AttInMetadata *attinmeta; SPITupleTable *spi_tuptable; TupleDesc spi_tupdesc; bool firstpass; char *lastrowid; int i; int num_categories; MemoryContext per_query_ctx; MemoryContext oldcontext; int ret; uint64 proc; /* check to see if caller supports us returning a tuplestore */ if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); if (!(rsinfo->allowedModes & SFRM_Materialize)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("materialize mode required, but it is not allowed in this context"))); per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; /* Connect to SPI manager */ if ((ret = SPI_connect()) < 0) /* internal error */ elog(ERROR, "crosstab: SPI_connect returned %d", ret); /* Retrieve the desired rows */ ret = SPI_execute(sql, true, 0); proc = SPI_processed; /* If no qualifying tuples, fall out early */ if (ret != SPI_OK_SELECT || proc == 0) { SPI_finish(); rsinfo->isDone = ExprEndResult; PG_RETURN_NULL(); } spi_tuptable = SPI_tuptable; spi_tupdesc = spi_tuptable->tupdesc; /*---------- * The provided SQL query must always return three columns. * * 1. rowname * the label or identifier for each row in the final result * 2. category * the label or identifier for each column in the final result * 3. values * the value for each column in the final result *---------- */ if (spi_tupdesc->natts != 3) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid source data SQL statement"), errdetail("The provided SQL must return 3 " "columns: rowid, category, and values."))); /* get a tuple descriptor for our result type */ switch (get_call_result_type(fcinfo, NULL, &tupdesc)) { case TYPEFUNC_COMPOSITE: /* success */ break; case TYPEFUNC_RECORD: /* failed to determine actual type of RECORD */ ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("function returning record called in context " "that cannot accept type record"))); break; default: /* result type isn't composite */ ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("return type must be a row type"))); break; } /* * Check that return tupdesc is compatible with the data we got from SPI, * at least based on number and type of attributes */ if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc)) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("return and sql tuple descriptions are " \ "incompatible"))); /* * switch to long-lived memory context */ oldcontext = MemoryContextSwitchTo(per_query_ctx); /* make sure we have a persistent copy of the result tupdesc */ tupdesc = CreateTupleDescCopy(tupdesc); /* initialize our tuplestore in long-lived context */ tupstore = tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random, false, work_mem); MemoryContextSwitchTo(oldcontext); /* * Generate attribute metadata needed later to produce tuples from raw C * strings */ attinmeta = TupleDescGetAttInMetadata(tupdesc); /* total number of tuples to be examined */ max_calls = proc; /* the return tuple always must have 1 rowid + num_categories columns */ num_categories = tupdesc->natts - 1; firstpass = true; lastrowid = NULL; for (call_cntr = 0; call_cntr < max_calls; call_cntr++) { bool skip_tuple = false; char **values; /* allocate and zero space */ values = (char **) palloc0((1 + num_categories) * sizeof(char *)); /* * now loop through the sql results and assign each value in sequence * to the next category */ for (i = 0; i < num_categories; i++) { HeapTuple spi_tuple; char *rowid; /* see if we've gone too far already */ if (call_cntr >= max_calls) break; /* get the next sql result tuple */ spi_tuple = spi_tuptable->vals[call_cntr]; /* get the rowid from the current sql result tuple */ rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1); /* * If this is the first pass through the values for this rowid, * set the first column to rowid */ if (i == 0) { xpstrdup(values[0], rowid); /* * Check to see if the rowid is the same as that of the last * tuple sent -- if so, skip this tuple entirely */ if (!firstpass && xstreq(lastrowid, rowid)) { xpfree(rowid); skip_tuple = true; break; } } /* * If rowid hasn't changed on us, continue building the output * tuple. */ if (xstreq(rowid, values[0])) { /* * Get the next category item value, which is always attribute * number three. * * Be careful to assign the value to the array index based on * which category we are presently processing. */ values[1 + i] = SPI_getvalue(spi_tuple, spi_tupdesc, 3); /* * increment the counter since we consume a row for each * category, but not for last pass because the outer loop will * do that for us */ if (i < (num_categories - 1)) call_cntr++; xpfree(rowid); } else { /* * We'll fill in NULLs for the missing values, but we need to * decrement the counter since this sql result row doesn't * belong to the current output tuple. */ call_cntr--; xpfree(rowid); break; } } if (!skip_tuple) { HeapTuple tuple; /* build the tuple and store it */ tuple = BuildTupleFromCStrings(attinmeta, values); tuplestore_puttuple(tupstore, tuple); heap_freetuple(tuple); } /* Remember current rowid */ xpfree(lastrowid); xpstrdup(lastrowid, values[0]); firstpass = false; /* Clean up */ for (i = 0; i < num_categories + 1; i++) if (values[i] != NULL) pfree(values[i]); pfree(values); } /* let the caller know we're sending back a tuplestore */ rsinfo->returnMode = SFRM_Materialize; rsinfo->setResult = tupstore; rsinfo->setDesc = tupdesc; /* release SPI related resources (and return to caller's context) */ SPI_finish(); return (Datum) 0; } /* * crosstab_hash - reimplement crosstab as materialized function and * properly deal with missing values (i.e. don't pack remaining * values to the left) * * crosstab - create a crosstab of rowids and values columns from a * SQL statement returning one rowid column, one category column, * and one value column. * * e.g. given sql which produces: * * rowid cat value * ------+-------+------- * row1 cat1 val1 * row1 cat2 val2 * row1 cat4 val4 * row2 cat1 val5 * row2 cat2 val6 * row2 cat3 val7 * row2 cat4 val8 * * crosstab returns: * <===== values columns =====> * rowid cat1 cat2 cat3 cat4 * ------+-------+-------+-------+------- * row1 val1 val2 null val4 * row2 val5 val6 val7 val8 * * NOTES: * 1. SQL result must be ordered by 1. * 2. The number of values columns depends on the tuple description * of the function's declared return type. * 3. Missing values (i.e. missing category) are filled in with nulls. * 4. Extra values (i.e. not in category results) are skipped. */ PG_FUNCTION_INFO_V1(crosstab_hash); Datum crosstab_hash(PG_FUNCTION_ARGS) { char *sql = text_to_cstring(PG_GETARG_TEXT_PP(0)); char *cats_sql = text_to_cstring(PG_GETARG_TEXT_PP(1)); ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; TupleDesc tupdesc; MemoryContext per_query_ctx; MemoryContext oldcontext; HTAB *crosstab_hash; /* check to see if caller supports us returning a tuplestore */ if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); if (!(rsinfo->allowedModes & SFRM_Materialize) || rsinfo->expectedDesc == NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("materialize mode required, but it is not allowed in this context"))); per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; oldcontext = MemoryContextSwitchTo(per_query_ctx); /* get the requested return tuple description */ tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc); /* * Check to make sure we have a reasonable tuple descriptor * * Note we will attempt to coerce the values into whatever the return * attribute type is and depend on the "in" function to complain if * needed. */ if (tupdesc->natts < 2) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("query-specified return tuple and " \ "crosstab function are not compatible"))); /* load up the categories hash table */ crosstab_hash = load_categories_hash(cats_sql, per_query_ctx); /* let the caller know we're sending back a tuplestore */ rsinfo->returnMode = SFRM_Materialize; /* now go build it */ rsinfo->setResult = get_crosstab_tuplestore(sql, crosstab_hash, tupdesc, per_query_ctx, rsinfo->allowedModes & SFRM_Materialize_Random); /* * SFRM_Materialize mode expects us to return a NULL Datum. The actual * tuples are in our tuplestore and passed back through rsinfo->setResult. * rsinfo->setDesc is set to the tuple description that we actually used * to build our tuples with, so the caller can verify we did what it was * expecting. */ rsinfo->setDesc = tupdesc; MemoryContextSwitchTo(oldcontext); return (Datum) 0; } /* * load up the categories hash table */ static HTAB * load_categories_hash(char *cats_sql, MemoryContext per_query_ctx) { HTAB *crosstab_hash; HASHCTL ctl; int ret; uint64 proc; MemoryContext SPIcontext; /* initialize the category hash table */ MemSet(&ctl, 0, sizeof(ctl)); ctl.keysize = MAX_CATNAME_LEN; ctl.entrysize = sizeof(crosstab_HashEnt); ctl.hcxt = per_query_ctx; /* * use INIT_CATS, defined above as a guess of how many hash table entries * to create, initially */ crosstab_hash = hash_create("crosstab hash", INIT_CATS, &ctl, HASH_ELEM | HASH_CONTEXT); /* Connect to SPI manager */ if ((ret = SPI_connect()) < 0) /* internal error */ elog(ERROR, "load_categories_hash: SPI_connect returned %d", ret); /* Retrieve the category name rows */ ret = SPI_execute(cats_sql, true, 0); proc = SPI_processed; /* Check for qualifying tuples */ if ((ret == SPI_OK_SELECT) && (proc > 0)) { SPITupleTable *spi_tuptable = SPI_tuptable; TupleDesc spi_tupdesc = spi_tuptable->tupdesc; uint64 i; /* * The provided categories SQL query must always return one column: * category - the label or identifier for each column */ if (spi_tupdesc->natts != 1) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("provided \"categories\" SQL must " \ "return 1 column of at least one row"))); for (i = 0; i < proc; i++) { crosstab_cat_desc *catdesc; char *catname; HeapTuple spi_tuple; /* get the next sql result tuple */ spi_tuple = spi_tuptable->vals[i]; /* get the category from the current sql result tuple */ catname = SPI_getvalue(spi_tuple, spi_tupdesc, 1); if (catname == NULL) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("provided \"categories\" SQL must " \ "not return NULL values"))); SPIcontext = MemoryContextSwitchTo(per_query_ctx); catdesc = (crosstab_cat_desc *) palloc(sizeof(crosstab_cat_desc)); catdesc->catname = catname; catdesc->attidx = i; /* Add the proc description block to the hashtable */ crosstab_HashTableInsert(crosstab_hash, catdesc); MemoryContextSwitchTo(SPIcontext); } } if (SPI_finish() != SPI_OK_FINISH) /* internal error */ elog(ERROR, "load_categories_hash: SPI_finish() failed"); return crosstab_hash; } /* * create and populate the crosstab tuplestore using the provided source query */ static Tuplestorestate * get_crosstab_tuplestore(char *sql, HTAB *crosstab_hash, TupleDesc tupdesc, MemoryContext per_query_ctx, bool randomAccess) { Tuplestorestate *tupstore; int num_categories = hash_get_num_entries(crosstab_hash); AttInMetadata *attinmeta = TupleDescGetAttInMetadata(tupdesc); char **values; HeapTuple tuple; int ret; uint64 proc; /* initialize our tuplestore (while still in query context!) */ tupstore = tuplestore_begin_heap(randomAccess, false, work_mem); /* Connect to SPI manager */ if ((ret = SPI_connect()) < 0) /* internal error */ elog(ERROR, "get_crosstab_tuplestore: SPI_connect returned %d", ret); /* Now retrieve the crosstab source rows */ ret = SPI_execute(sql, true, 0); proc = SPI_processed; /* Check for qualifying tuples */ if ((ret == SPI_OK_SELECT) && (proc > 0)) { SPITupleTable *spi_tuptable = SPI_tuptable; TupleDesc spi_tupdesc = spi_tuptable->tupdesc; int ncols = spi_tupdesc->natts; char *rowid; char *lastrowid = NULL; bool firstpass = true; uint64 i; int j; int result_ncols; if (num_categories == 0) { /* no qualifying category tuples */ ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("provided \"categories\" SQL must " \ "return 1 column of at least one row"))); } /* * The provided SQL query must always return at least three columns: * * 1. rowname the label for each row - column 1 in the final result * 2. category the label for each value-column in the final result 3. * value the values used to populate the value-columns * * If there are more than three columns, the last two are taken as * "category" and "values". The first column is taken as "rowname". * Additional columns (2 thru N-2) are assumed the same for the same * "rowname", and are copied into the result tuple from the first time * we encounter a particular rowname. */ if (ncols < 3) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid source data SQL statement"), errdetail("The provided SQL must return 3 " \ " columns; rowid, category, and values."))); result_ncols = (ncols - 2) + num_categories; /* Recheck to make sure we tuple descriptor still looks reasonable */ if (tupdesc->natts != result_ncols) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("invalid return type"), errdetail("Query-specified return " \ "tuple has %d columns but crosstab " \ "returns %d.", tupdesc->natts, result_ncols))); /* allocate space and make sure it's clear */ values = (char **) palloc0(result_ncols * sizeof(char *)); for (i = 0; i < proc; i++) { HeapTuple spi_tuple; crosstab_cat_desc *catdesc; char *catname; /* get the next sql result tuple */ spi_tuple = spi_tuptable->vals[i]; /* get the rowid from the current sql result tuple */ rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1); /* * if we're on a new output row, grab the column values up to * column N-2 now */ if (firstpass || !xstreq(lastrowid, rowid)) { /* * a new row means we need to flush the old one first, unless * we're on the very first row */ if (!firstpass) { /* rowid changed, flush the previous output row */ tuple = BuildTupleFromCStrings(attinmeta, values); tuplestore_puttuple(tupstore, tuple); for (j = 0; j < result_ncols; j++) xpfree(values[j]); } values[0] = rowid; for (j = 1; j < ncols - 2; j++) values[j] = SPI_getvalue(spi_tuple, spi_tupdesc, j + 1); /* we're no longer on the first pass */ firstpass = false; } /* look up the category and fill in the appropriate column */ catname = SPI_getvalue(spi_tuple, spi_tupdesc, ncols - 1); if (catname != NULL) { crosstab_HashTableLookup(crosstab_hash, catname, catdesc); if (catdesc) values[catdesc->attidx + ncols - 2] = SPI_getvalue(spi_tuple, spi_tupdesc, ncols); } xpfree(lastrowid); xpstrdup(lastrowid, rowid); } /* flush the last output row */ tuple = BuildTupleFromCStrings(attinmeta, values); tuplestore_puttuple(tupstore, tuple); } if (SPI_finish() != SPI_OK_FINISH) /* internal error */ elog(ERROR, "get_crosstab_tuplestore: SPI_finish() failed"); tuplestore_donestoring(tupstore); return tupstore; } /* * connectby_text - produce a result set from a hierarchical (parent/child) * table. * * e.g. given table foo: * * keyid parent_keyid pos * ------+------------+-- * row1 NULL 0 * row2 row1 0 * row3 row1 0 * row4 row2 1 * row5 row2 0 * row6 row4 0 * row7 row3 0 * row8 row6 0 * row9 row5 0 * * * connectby(text relname, text keyid_fld, text parent_keyid_fld * [, text orderby_fld], text start_with, int max_depth * [, text branch_delim]) * connectby('foo', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') returns: * * keyid parent_id level branch serial * ------+-----------+--------+----------------------- * row2 NULL 0 row2 1 * row5 row2 1 row2~row5 2 * row9 row5 2 row2~row5~row9 3 * row4 row2 1 row2~row4 4 * row6 row4 2 row2~row4~row6 5 * row8 row6 3 row2~row4~row6~row8 6 * */ PG_FUNCTION_INFO_V1(connectby_text); #define CONNECTBY_NCOLS 4 #define CONNECTBY_NCOLS_NOBRANCH 3 Datum connectby_text(PG_FUNCTION_ARGS) { char *relname = text_to_cstring(PG_GETARG_TEXT_PP(0)); char *key_fld = text_to_cstring(PG_GETARG_TEXT_PP(1)); char *parent_key_fld = text_to_cstring(PG_GETARG_TEXT_PP(2)); char *start_with = text_to_cstring(PG_GETARG_TEXT_PP(3)); int max_depth = PG_GETARG_INT32(4); char *branch_delim = NULL; bool show_branch = false; bool show_serial = false; ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; TupleDesc tupdesc; AttInMetadata *attinmeta; MemoryContext per_query_ctx; MemoryContext oldcontext; /* check to see if caller supports us returning a tuplestore */ if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); if (!(rsinfo->allowedModes & SFRM_Materialize) || rsinfo->expectedDesc == NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("materialize mode required, but it is not allowed in this context"))); if (fcinfo->nargs == 6) { branch_delim = text_to_cstring(PG_GETARG_TEXT_PP(5)); show_branch = true; } else /* default is no show, tilde for the delimiter */ branch_delim = pstrdup("~"); per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; oldcontext = MemoryContextSwitchTo(per_query_ctx); /* get the requested return tuple description */ tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc); /* does it meet our needs */ validateConnectbyTupleDesc(tupdesc, show_branch, show_serial); /* OK, use it then */ attinmeta = TupleDescGetAttInMetadata(tupdesc); /* OK, go to work */ rsinfo->returnMode = SFRM_Materialize; rsinfo->setResult = connectby(relname, key_fld, parent_key_fld, NULL, branch_delim, start_with, max_depth, show_branch, show_serial, per_query_ctx, rsinfo->allowedModes & SFRM_Materialize_Random, attinmeta); rsinfo->setDesc = tupdesc; MemoryContextSwitchTo(oldcontext); /* * SFRM_Materialize mode expects us to return a NULL Datum. The actual * tuples are in our tuplestore and passed back through rsinfo->setResult. * rsinfo->setDesc is set to the tuple description that we actually used * to build our tuples with, so the caller can verify we did what it was * expecting. */ return (Datum) 0; } PG_FUNCTION_INFO_V1(connectby_text_serial); Datum connectby_text_serial(PG_FUNCTION_ARGS) { char *relname = text_to_cstring(PG_GETARG_TEXT_PP(0)); char *key_fld = text_to_cstring(PG_GETARG_TEXT_PP(1)); char *parent_key_fld = text_to_cstring(PG_GETARG_TEXT_PP(2)); char *orderby_fld = text_to_cstring(PG_GETARG_TEXT_PP(3)); char *start_with = text_to_cstring(PG_GETARG_TEXT_PP(4)); int max_depth = PG_GETARG_INT32(5); char *branch_delim = NULL; bool show_branch = false; bool show_serial = true; ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; TupleDesc tupdesc; AttInMetadata *attinmeta; MemoryContext per_query_ctx; MemoryContext oldcontext; /* check to see if caller supports us returning a tuplestore */ if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("set-valued function called in context that cannot accept a set"))); if (!(rsinfo->allowedModes & SFRM_Materialize) || rsinfo->expectedDesc == NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("materialize mode required, but it is not allowed in this context"))); if (fcinfo->nargs == 7) { branch_delim = text_to_cstring(PG_GETARG_TEXT_PP(6)); show_branch = true; } else /* default is no show, tilde for the delimiter */ branch_delim = pstrdup("~"); per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; oldcontext = MemoryContextSwitchTo(per_query_ctx); /* get the requested return tuple description */ tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc); /* does it meet our needs */ validateConnectbyTupleDesc(tupdesc, show_branch, show_serial); /* OK, use it then */ attinmeta = TupleDescGetAttInMetadata(tupdesc); /* OK, go to work */ rsinfo->returnMode = SFRM_Materialize; rsinfo->setResult = connectby(relname, key_fld, parent_key_fld, orderby_fld, branch_delim, start_with, max_depth, show_branch, show_serial, per_query_ctx, rsinfo->allowedModes & SFRM_Materialize_Random, attinmeta); rsinfo->setDesc = tupdesc; MemoryContextSwitchTo(oldcontext); /* * SFRM_Materialize mode expects us to return a NULL Datum. The actual * tuples are in our tuplestore and passed back through rsinfo->setResult. * rsinfo->setDesc is set to the tuple description that we actually used * to build our tuples with, so the caller can verify we did what it was * expecting. */ return (Datum) 0; } /* * connectby - does the real work for connectby_text() */ static Tuplestorestate * connectby(char *relname, char *key_fld, char *parent_key_fld, char *orderby_fld, char *branch_delim, char *start_with, int max_depth, bool show_branch, bool show_serial, MemoryContext per_query_ctx, bool randomAccess, AttInMetadata *attinmeta) { Tuplestorestate *tupstore = NULL; int ret; MemoryContext oldcontext; int serial = 1; /* Connect to SPI manager */ if ((ret = SPI_connect()) < 0) /* internal error */ elog(ERROR, "connectby: SPI_connect returned %d", ret); /* switch to longer term context to create the tuple store */ oldcontext = MemoryContextSwitchTo(per_query_ctx); /* initialize our tuplestore */ tupstore = tuplestore_begin_heap(randomAccess, false, work_mem); MemoryContextSwitchTo(oldcontext); /* now go get the whole tree */ build_tuplestore_recursively(key_fld, parent_key_fld, relname, orderby_fld, branch_delim, start_with, start_with, /* current_branch */ 0, /* initial level is 0 */ &serial, /* initial serial is 1 */ max_depth, show_branch, show_serial, per_query_ctx, attinmeta, tupstore); SPI_finish(); return tupstore; } static void build_tuplestore_recursively(char *key_fld, char *parent_key_fld, char *relname, char *orderby_fld, char *branch_delim, char *start_with, char *branch, int level, int *serial, int max_depth, bool show_branch, bool show_serial, MemoryContext per_query_ctx, AttInMetadata *attinmeta, Tuplestorestate *tupstore) { TupleDesc tupdesc = attinmeta->tupdesc; int ret; uint64 proc; int serial_column; StringInfoData sql; char **values; char *current_key; char *current_key_parent; char current_level[INT32_STRLEN]; char serial_str[INT32_STRLEN]; char *current_branch; HeapTuple tuple; if (max_depth > 0 && level > max_depth) return; initStringInfo(&sql); /* Build initial sql statement */ if (!show_serial) { appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s", key_fld, parent_key_fld, relname, parent_key_fld, quote_literal_cstr(start_with), key_fld, key_fld, parent_key_fld); serial_column = 0; } else { appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s ORDER BY %s", key_fld, parent_key_fld, relname, parent_key_fld, quote_literal_cstr(start_with), key_fld, key_fld, parent_key_fld, orderby_fld); serial_column = 1; } if (show_branch) values = (char **) palloc((CONNECTBY_NCOLS + serial_column) * sizeof(char *)); else values = (char **) palloc((CONNECTBY_NCOLS_NOBRANCH + serial_column) * sizeof(char *)); /* First time through, do a little setup */ if (level == 0) { /* root value is the one we initially start with */ values[0] = start_with; /* root value has no parent */ values[1] = NULL; /* root level is 0 */ sprintf(current_level, "%d", level); values[2] = current_level; /* root branch is just starting root value */ if (show_branch) values[3] = start_with; /* root starts the serial with 1 */ if (show_serial) { sprintf(serial_str, "%d", (*serial)++); if (show_branch) values[4] = serial_str; else values[3] = serial_str; } /* construct the tuple */ tuple = BuildTupleFromCStrings(attinmeta, values); /* now store it */ tuplestore_puttuple(tupstore, tuple); /* increment level */ level++; } /* Retrieve the desired rows */ ret = SPI_execute(sql.data, true, 0); proc = SPI_processed; /* Check for qualifying tuples */ if ((ret == SPI_OK_SELECT) && (proc > 0)) { HeapTuple spi_tuple; SPITupleTable *tuptable = SPI_tuptable; TupleDesc spi_tupdesc = tuptable->tupdesc; uint64 i; StringInfoData branchstr; StringInfoData chk_branchstr; StringInfoData chk_current_key; /* * Check that return tupdesc is compatible with the one we got from * the query. */ compatConnectbyTupleDescs(tupdesc, spi_tupdesc); initStringInfo(&branchstr); initStringInfo(&chk_branchstr); initStringInfo(&chk_current_key); for (i = 0; i < proc; i++) { /* initialize branch for this pass */ appendStringInfoString(&branchstr, branch); appendStringInfo(&chk_branchstr, "%s%s%s", branch_delim, branch, branch_delim); /* get the next sql result tuple */ spi_tuple = tuptable->vals[i]; /* get the current key (might be NULL) */ current_key = SPI_getvalue(spi_tuple, spi_tupdesc, 1); /* get the parent key (might be NULL) */ current_key_parent = SPI_getvalue(spi_tuple, spi_tupdesc, 2); /* get the current level */ sprintf(current_level, "%d", level); /* check to see if this key is also an ancestor */ if (current_key) { appendStringInfo(&chk_current_key, "%s%s%s", branch_delim, current_key, branch_delim); if (strstr(chk_branchstr.data, chk_current_key.data)) ereport(ERROR, (errcode(ERRCODE_INVALID_RECURSION), errmsg("infinite recursion detected"))); } /* OK, extend the branch */ if (current_key) appendStringInfo(&branchstr, "%s%s", branch_delim, current_key); current_branch = branchstr.data; /* build a tuple */ values[0] = current_key; values[1] = current_key_parent; values[2] = current_level; if (show_branch) values[3] = current_branch; if (show_serial) { sprintf(serial_str, "%d", (*serial)++); if (show_branch) values[4] = serial_str; else values[3] = serial_str; } tuple = BuildTupleFromCStrings(attinmeta, values); /* store the tuple for later use */ tuplestore_puttuple(tupstore, tuple); heap_freetuple(tuple); /* recurse using current_key as the new start_with */ if (current_key) build_tuplestore_recursively(key_fld, parent_key_fld, relname, orderby_fld, branch_delim, current_key, current_branch, level + 1, serial, max_depth, show_branch, show_serial, per_query_ctx, attinmeta, tupstore); xpfree(current_key); xpfree(current_key_parent); /* reset branch for next pass */ resetStringInfo(&branchstr); resetStringInfo(&chk_branchstr); resetStringInfo(&chk_current_key); } xpfree(branchstr.data); xpfree(chk_branchstr.data); xpfree(chk_current_key.data); } } /* * Check expected (query runtime) tupdesc suitable for Connectby */ static void validateConnectbyTupleDesc(TupleDesc td, bool show_branch, bool show_serial) { int serial_column = 0; if (show_serial) serial_column = 1; /* are there the correct number of columns */ if (show_branch) { if (td->natts != (CONNECTBY_NCOLS + serial_column)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("Query-specified return tuple has " \ "wrong number of columns."))); } else { if (td->natts != CONNECTBY_NCOLS_NOBRANCH + serial_column) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("Query-specified return tuple has " \ "wrong number of columns."))); } /* check that the types of the first two columns match */ if (TupleDescAttr(td, 0)->atttypid != TupleDescAttr(td, 1)->atttypid) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("First two columns must be the same type."))); /* check that the type of the third column is INT4 */ if (TupleDescAttr(td, 2)->atttypid != INT4OID) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("Third column must be type %s.", format_type_be(INT4OID)))); /* check that the type of the fourth column is TEXT if applicable */ if (show_branch && TupleDescAttr(td, 3)->atttypid != TEXTOID) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("Fourth column must be type %s.", format_type_be(TEXTOID)))); /* check that the type of the fifth column is INT4 */ if (show_branch && show_serial && TupleDescAttr(td, 4)->atttypid != INT4OID) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("query-specified return tuple not valid for Connectby: " "fifth column must be type %s", format_type_be(INT4OID)))); /* check that the type of the fifth column is INT4 */ if (!show_branch && show_serial && TupleDescAttr(td, 3)->atttypid != INT4OID) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("query-specified return tuple not valid for Connectby: " "fourth column must be type %s", format_type_be(INT4OID)))); /* OK, the tupdesc is valid for our purposes */ } /* * Check if spi sql tupdesc and return tupdesc are compatible */ static void compatConnectbyTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc) { Oid ret_atttypid; Oid sql_atttypid; int32 ret_atttypmod; int32 sql_atttypmod; /* * Result must have at least 2 columns. */ if (sql_tupdesc->natts < 2) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("Query must return at least two columns."))); /* * These columns must match the result type indicated by the calling * query. */ ret_atttypid = TupleDescAttr(ret_tupdesc, 0)->atttypid; sql_atttypid = TupleDescAttr(sql_tupdesc, 0)->atttypid; ret_atttypmod = TupleDescAttr(ret_tupdesc, 0)->atttypmod; sql_atttypmod = TupleDescAttr(sql_tupdesc, 0)->atttypmod; if (ret_atttypid != sql_atttypid || (ret_atttypmod >= 0 && ret_atttypmod != sql_atttypmod)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("SQL key field type %s does " \ "not match return key field type %s.", format_type_with_typemod(ret_atttypid, ret_atttypmod), format_type_with_typemod(sql_atttypid, sql_atttypmod)))); ret_atttypid = TupleDescAttr(ret_tupdesc, 1)->atttypid; sql_atttypid = TupleDescAttr(sql_tupdesc, 1)->atttypid; ret_atttypmod = TupleDescAttr(ret_tupdesc, 1)->atttypmod; sql_atttypmod = TupleDescAttr(sql_tupdesc, 1)->atttypmod; if (ret_atttypid != sql_atttypid || (ret_atttypmod >= 0 && ret_atttypmod != sql_atttypmod)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("SQL parent key field type %s does " \ "not match return parent key field type %s.", format_type_with_typemod(ret_atttypid, ret_atttypmod), format_type_with_typemod(sql_atttypid, sql_atttypmod)))); /* OK, the two tupdescs are compatible for our purposes */ } /* * Check if two tupdescs match in type of attributes */ static bool compatCrosstabTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc) { int i; Form_pg_attribute ret_attr; Oid ret_atttypid; Form_pg_attribute sql_attr; Oid sql_atttypid; if (ret_tupdesc->natts < 2 || sql_tupdesc->natts < 3) return false; /* check the rowid types match */ ret_atttypid = TupleDescAttr(ret_tupdesc, 0)->atttypid; sql_atttypid = TupleDescAttr(sql_tupdesc, 0)->atttypid; if (ret_atttypid != sql_atttypid) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("invalid return type"), errdetail("SQL rowid datatype does not match " \ "return rowid datatype."))); /* * - attribute [1] of the sql tuple is the category; no need to check it - * attribute [2] of the sql tuple should match attributes [1] to [natts] * of the return tuple */ sql_attr = TupleDescAttr(sql_tupdesc, 2); for (i = 1; i < ret_tupdesc->natts; i++) { ret_attr = TupleDescAttr(ret_tupdesc, i); if (ret_attr->atttypid != sql_attr->atttypid) return false; } /* OK, the two tupdescs are compatible for our purposes */ return true; }