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-rw-r--r--src/interfaces/libpq/fe-exec.c4451
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diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
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+++ b/src/interfaces/libpq/fe-exec.c
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+/*-------------------------------------------------------------------------
+ *
+ * fe-exec.c
+ * functions related to sending a query down to the backend
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/interfaces/libpq/fe-exec.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres_fe.h"
+
+#include <ctype.h>
+#include <fcntl.h>
+#include <limits.h>
+
+#ifdef WIN32
+#include "win32.h"
+#else
+#include <unistd.h>
+#endif
+
+#include "libpq-fe.h"
+#include "libpq-int.h"
+#include "mb/pg_wchar.h"
+
+/* keep this in same order as ExecStatusType in libpq-fe.h */
+char *const pgresStatus[] = {
+ "PGRES_EMPTY_QUERY",
+ "PGRES_COMMAND_OK",
+ "PGRES_TUPLES_OK",
+ "PGRES_COPY_OUT",
+ "PGRES_COPY_IN",
+ "PGRES_BAD_RESPONSE",
+ "PGRES_NONFATAL_ERROR",
+ "PGRES_FATAL_ERROR",
+ "PGRES_COPY_BOTH",
+ "PGRES_SINGLE_TUPLE",
+ "PGRES_PIPELINE_SYNC",
+ "PGRES_PIPELINE_ABORTED"
+};
+
+/*
+ * static state needed by PQescapeString and PQescapeBytea; initialize to
+ * values that result in backward-compatible behavior
+ */
+static int static_client_encoding = PG_SQL_ASCII;
+static bool static_std_strings = false;
+
+
+static PGEvent *dupEvents(PGEvent *events, int count, size_t *memSize);
+static bool pqAddTuple(PGresult *res, PGresAttValue *tup,
+ const char **errmsgp);
+static int PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery);
+static bool PQsendQueryStart(PGconn *conn, bool newQuery);
+static int PQsendQueryGuts(PGconn *conn,
+ const char *command,
+ const char *stmtName,
+ int nParams,
+ const Oid *paramTypes,
+ const char *const *paramValues,
+ const int *paramLengths,
+ const int *paramFormats,
+ int resultFormat);
+static void parseInput(PGconn *conn);
+static PGresult *getCopyResult(PGconn *conn, ExecStatusType copytype);
+static bool PQexecStart(PGconn *conn);
+static PGresult *PQexecFinish(PGconn *conn);
+static int PQsendDescribe(PGconn *conn, char desc_type,
+ const char *desc_target);
+static int check_field_number(const PGresult *res, int field_num);
+static void pqPipelineProcessQueue(PGconn *conn);
+static int pqPipelineFlush(PGconn *conn);
+
+
+/* ----------------
+ * Space management for PGresult.
+ *
+ * Formerly, libpq did a separate malloc() for each field of each tuple
+ * returned by a query. This was remarkably expensive --- malloc/free
+ * consumed a sizable part of the application's runtime. And there is
+ * no real need to keep track of the fields separately, since they will
+ * all be freed together when the PGresult is released. So now, we grab
+ * large blocks of storage from malloc and allocate space for query data
+ * within these blocks, using a trivially simple allocator. This reduces
+ * the number of malloc/free calls dramatically, and it also avoids
+ * fragmentation of the malloc storage arena.
+ * The PGresult structure itself is still malloc'd separately. We could
+ * combine it with the first allocation block, but that would waste space
+ * for the common case that no extra storage is actually needed (that is,
+ * the SQL command did not return tuples).
+ *
+ * We also malloc the top-level array of tuple pointers separately, because
+ * we need to be able to enlarge it via realloc, and our trivial space
+ * allocator doesn't handle that effectively. (Too bad the FE/BE protocol
+ * doesn't tell us up front how many tuples will be returned.)
+ * All other subsidiary storage for a PGresult is kept in PGresult_data blocks
+ * of size PGRESULT_DATA_BLOCKSIZE. The overhead at the start of each block
+ * is just a link to the next one, if any. Free-space management info is
+ * kept in the owning PGresult.
+ * A query returning a small amount of data will thus require three malloc
+ * calls: one for the PGresult, one for the tuples pointer array, and one
+ * PGresult_data block.
+ *
+ * Only the most recently allocated PGresult_data block is a candidate to
+ * have more stuff added to it --- any extra space left over in older blocks
+ * is wasted. We could be smarter and search the whole chain, but the point
+ * here is to be simple and fast. Typical applications do not keep a PGresult
+ * around very long anyway, so some wasted space within one is not a problem.
+ *
+ * Tuning constants for the space allocator are:
+ * PGRESULT_DATA_BLOCKSIZE: size of a standard allocation block, in bytes
+ * PGRESULT_ALIGN_BOUNDARY: assumed alignment requirement for binary data
+ * PGRESULT_SEP_ALLOC_THRESHOLD: objects bigger than this are given separate
+ * blocks, instead of being crammed into a regular allocation block.
+ * Requirements for correct function are:
+ * PGRESULT_ALIGN_BOUNDARY must be a multiple of the alignment requirements
+ * of all machine data types. (Currently this is set from configure
+ * tests, so it should be OK automatically.)
+ * PGRESULT_SEP_ALLOC_THRESHOLD + PGRESULT_BLOCK_OVERHEAD <=
+ * PGRESULT_DATA_BLOCKSIZE
+ * pqResultAlloc assumes an object smaller than the threshold will fit
+ * in a new block.
+ * The amount of space wasted at the end of a block could be as much as
+ * PGRESULT_SEP_ALLOC_THRESHOLD, so it doesn't pay to make that too large.
+ * ----------------
+ */
+
+#define PGRESULT_DATA_BLOCKSIZE 2048
+#define PGRESULT_ALIGN_BOUNDARY MAXIMUM_ALIGNOF /* from configure */
+#define PGRESULT_BLOCK_OVERHEAD Max(sizeof(PGresult_data), PGRESULT_ALIGN_BOUNDARY)
+#define PGRESULT_SEP_ALLOC_THRESHOLD (PGRESULT_DATA_BLOCKSIZE / 2)
+
+
+/*
+ * PQmakeEmptyPGresult
+ * returns a newly allocated, initialized PGresult with given status.
+ * If conn is not NULL and status indicates an error, the conn's
+ * errorMessage is copied. Also, any PGEvents are copied from the conn.
+ */
+PGresult *
+PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status)
+{
+ PGresult *result;
+
+ result = (PGresult *) malloc(sizeof(PGresult));
+ if (!result)
+ return NULL;
+
+ result->ntups = 0;
+ result->numAttributes = 0;
+ result->attDescs = NULL;
+ result->tuples = NULL;
+ result->tupArrSize = 0;
+ result->numParameters = 0;
+ result->paramDescs = NULL;
+ result->resultStatus = status;
+ result->cmdStatus[0] = '\0';
+ result->binary = 0;
+ result->events = NULL;
+ result->nEvents = 0;
+ result->errMsg = NULL;
+ result->errFields = NULL;
+ result->errQuery = NULL;
+ result->null_field[0] = '\0';
+ result->curBlock = NULL;
+ result->curOffset = 0;
+ result->spaceLeft = 0;
+ result->memorySize = sizeof(PGresult);
+
+ if (conn)
+ {
+ /* copy connection data we might need for operations on PGresult */
+ result->noticeHooks = conn->noticeHooks;
+ result->client_encoding = conn->client_encoding;
+
+ /* consider copying conn's errorMessage */
+ switch (status)
+ {
+ case PGRES_EMPTY_QUERY:
+ case PGRES_COMMAND_OK:
+ case PGRES_TUPLES_OK:
+ case PGRES_COPY_OUT:
+ case PGRES_COPY_IN:
+ case PGRES_COPY_BOTH:
+ case PGRES_SINGLE_TUPLE:
+ /* non-error cases */
+ break;
+ default:
+ pqSetResultError(result, &conn->errorMessage);
+ break;
+ }
+
+ /* copy events last; result must be valid if we need to PQclear */
+ if (conn->nEvents > 0)
+ {
+ result->events = dupEvents(conn->events, conn->nEvents,
+ &result->memorySize);
+ if (!result->events)
+ {
+ PQclear(result);
+ return NULL;
+ }
+ result->nEvents = conn->nEvents;
+ }
+ }
+ else
+ {
+ /* defaults... */
+ result->noticeHooks.noticeRec = NULL;
+ result->noticeHooks.noticeRecArg = NULL;
+ result->noticeHooks.noticeProc = NULL;
+ result->noticeHooks.noticeProcArg = NULL;
+ result->client_encoding = PG_SQL_ASCII;
+ }
+
+ return result;
+}
+
+/*
+ * PQsetResultAttrs
+ *
+ * Set the attributes for a given result. This function fails if there are
+ * already attributes contained in the provided result. The call is
+ * ignored if numAttributes is zero or attDescs is NULL. If the
+ * function fails, it returns zero. If the function succeeds, it
+ * returns a non-zero value.
+ */
+int
+PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs)
+{
+ int i;
+
+ /* If attrs already exist, they cannot be overwritten. */
+ if (!res || res->numAttributes > 0)
+ return false;
+
+ /* ignore no-op request */
+ if (numAttributes <= 0 || !attDescs)
+ return true;
+
+ res->attDescs = (PGresAttDesc *)
+ PQresultAlloc(res, numAttributes * sizeof(PGresAttDesc));
+
+ if (!res->attDescs)
+ return false;
+
+ res->numAttributes = numAttributes;
+ memcpy(res->attDescs, attDescs, numAttributes * sizeof(PGresAttDesc));
+
+ /* deep-copy the attribute names, and determine format */
+ res->binary = 1;
+ for (i = 0; i < res->numAttributes; i++)
+ {
+ if (res->attDescs[i].name)
+ res->attDescs[i].name = pqResultStrdup(res, res->attDescs[i].name);
+ else
+ res->attDescs[i].name = res->null_field;
+
+ if (!res->attDescs[i].name)
+ return false;
+
+ if (res->attDescs[i].format == 0)
+ res->binary = 0;
+ }
+
+ return true;
+}
+
+/*
+ * PQcopyResult
+ *
+ * Returns a deep copy of the provided 'src' PGresult, which cannot be NULL.
+ * The 'flags' argument controls which portions of the result will or will
+ * NOT be copied. The created result is always put into the
+ * PGRES_TUPLES_OK status. The source result error message is not copied,
+ * although cmdStatus is.
+ *
+ * To set custom attributes, use PQsetResultAttrs. That function requires
+ * that there are no attrs contained in the result, so to use that
+ * function you cannot use the PG_COPYRES_ATTRS or PG_COPYRES_TUPLES
+ * options with this function.
+ *
+ * Options:
+ * PG_COPYRES_ATTRS - Copy the source result's attributes
+ *
+ * PG_COPYRES_TUPLES - Copy the source result's tuples. This implies
+ * copying the attrs, seeing how the attrs are needed by the tuples.
+ *
+ * PG_COPYRES_EVENTS - Copy the source result's events.
+ *
+ * PG_COPYRES_NOTICEHOOKS - Copy the source result's notice hooks.
+ */
+PGresult *
+PQcopyResult(const PGresult *src, int flags)
+{
+ PGresult *dest;
+ int i;
+
+ if (!src)
+ return NULL;
+
+ dest = PQmakeEmptyPGresult(NULL, PGRES_TUPLES_OK);
+ if (!dest)
+ return NULL;
+
+ /* Always copy these over. Is cmdStatus really useful here? */
+ dest->client_encoding = src->client_encoding;
+ strcpy(dest->cmdStatus, src->cmdStatus);
+
+ /* Wants attrs? */
+ if (flags & (PG_COPYRES_ATTRS | PG_COPYRES_TUPLES))
+ {
+ if (!PQsetResultAttrs(dest, src->numAttributes, src->attDescs))
+ {
+ PQclear(dest);
+ return NULL;
+ }
+ }
+
+ /* Wants to copy tuples? */
+ if (flags & PG_COPYRES_TUPLES)
+ {
+ int tup,
+ field;
+
+ for (tup = 0; tup < src->ntups; tup++)
+ {
+ for (field = 0; field < src->numAttributes; field++)
+ {
+ if (!PQsetvalue(dest, tup, field,
+ src->tuples[tup][field].value,
+ src->tuples[tup][field].len))
+ {
+ PQclear(dest);
+ return NULL;
+ }
+ }
+ }
+ }
+
+ /* Wants to copy notice hooks? */
+ if (flags & PG_COPYRES_NOTICEHOOKS)
+ dest->noticeHooks = src->noticeHooks;
+
+ /* Wants to copy PGEvents? */
+ if ((flags & PG_COPYRES_EVENTS) && src->nEvents > 0)
+ {
+ dest->events = dupEvents(src->events, src->nEvents,
+ &dest->memorySize);
+ if (!dest->events)
+ {
+ PQclear(dest);
+ return NULL;
+ }
+ dest->nEvents = src->nEvents;
+ }
+
+ /* Okay, trigger PGEVT_RESULTCOPY event */
+ for (i = 0; i < dest->nEvents; i++)
+ {
+ if (src->events[i].resultInitialized)
+ {
+ PGEventResultCopy evt;
+
+ evt.src = src;
+ evt.dest = dest;
+ if (!dest->events[i].proc(PGEVT_RESULTCOPY, &evt,
+ dest->events[i].passThrough))
+ {
+ PQclear(dest);
+ return NULL;
+ }
+ dest->events[i].resultInitialized = true;
+ }
+ }
+
+ return dest;
+}
+
+/*
+ * Copy an array of PGEvents (with no extra space for more).
+ * Does not duplicate the event instance data, sets this to NULL.
+ * Also, the resultInitialized flags are all cleared.
+ * The total space allocated is added to *memSize.
+ */
+static PGEvent *
+dupEvents(PGEvent *events, int count, size_t *memSize)
+{
+ PGEvent *newEvents;
+ size_t msize;
+ int i;
+
+ if (!events || count <= 0)
+ return NULL;
+
+ msize = count * sizeof(PGEvent);
+ newEvents = (PGEvent *) malloc(msize);
+ if (!newEvents)
+ return NULL;
+
+ for (i = 0; i < count; i++)
+ {
+ newEvents[i].proc = events[i].proc;
+ newEvents[i].passThrough = events[i].passThrough;
+ newEvents[i].data = NULL;
+ newEvents[i].resultInitialized = false;
+ newEvents[i].name = strdup(events[i].name);
+ if (!newEvents[i].name)
+ {
+ while (--i >= 0)
+ free(newEvents[i].name);
+ free(newEvents);
+ return NULL;
+ }
+ msize += strlen(events[i].name) + 1;
+ }
+
+ *memSize += msize;
+ return newEvents;
+}
+
+
+/*
+ * Sets the value for a tuple field. The tup_num must be less than or
+ * equal to PQntuples(res). If it is equal, a new tuple is created and
+ * added to the result.
+ * Returns a non-zero value for success and zero for failure.
+ * (On failure, we report the specific problem via pqInternalNotice.)
+ */
+int
+PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len)
+{
+ PGresAttValue *attval;
+ const char *errmsg = NULL;
+
+ /* Note that this check also protects us against null "res" */
+ if (!check_field_number(res, field_num))
+ return false;
+
+ /* Invalid tup_num, must be <= ntups */
+ if (tup_num < 0 || tup_num > res->ntups)
+ {
+ pqInternalNotice(&res->noticeHooks,
+ "row number %d is out of range 0..%d",
+ tup_num, res->ntups);
+ return false;
+ }
+
+ /* need to allocate a new tuple? */
+ if (tup_num == res->ntups)
+ {
+ PGresAttValue *tup;
+ int i;
+
+ tup = (PGresAttValue *)
+ pqResultAlloc(res, res->numAttributes * sizeof(PGresAttValue),
+ true);
+
+ if (!tup)
+ goto fail;
+
+ /* initialize each column to NULL */
+ for (i = 0; i < res->numAttributes; i++)
+ {
+ tup[i].len = NULL_LEN;
+ tup[i].value = res->null_field;
+ }
+
+ /* add it to the array */
+ if (!pqAddTuple(res, tup, &errmsg))
+ goto fail;
+ }
+
+ attval = &res->tuples[tup_num][field_num];
+
+ /* treat either NULL_LEN or NULL value pointer as a NULL field */
+ if (len == NULL_LEN || value == NULL)
+ {
+ attval->len = NULL_LEN;
+ attval->value = res->null_field;
+ }
+ else if (len <= 0)
+ {
+ attval->len = 0;
+ attval->value = res->null_field;
+ }
+ else
+ {
+ attval->value = (char *) pqResultAlloc(res, len + 1, true);
+ if (!attval->value)
+ goto fail;
+ attval->len = len;
+ memcpy(attval->value, value, len);
+ attval->value[len] = '\0';
+ }
+
+ return true;
+
+ /*
+ * Report failure via pqInternalNotice. If preceding code didn't provide
+ * an error message, assume "out of memory" was meant.
+ */
+fail:
+ if (!errmsg)
+ errmsg = libpq_gettext("out of memory");
+ pqInternalNotice(&res->noticeHooks, "%s", errmsg);
+
+ return false;
+}
+
+/*
+ * pqResultAlloc - exported routine to allocate local storage in a PGresult.
+ *
+ * We force all such allocations to be maxaligned, since we don't know
+ * whether the value might be binary.
+ */
+void *
+PQresultAlloc(PGresult *res, size_t nBytes)
+{
+ return pqResultAlloc(res, nBytes, true);
+}
+
+/*
+ * pqResultAlloc -
+ * Allocate subsidiary storage for a PGresult.
+ *
+ * nBytes is the amount of space needed for the object.
+ * If isBinary is true, we assume that we need to align the object on
+ * a machine allocation boundary.
+ * If isBinary is false, we assume the object is a char string and can
+ * be allocated on any byte boundary.
+ */
+void *
+pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary)
+{
+ char *space;
+ PGresult_data *block;
+
+ if (!res)
+ return NULL;
+
+ if (nBytes <= 0)
+ return res->null_field;
+
+ /*
+ * If alignment is needed, round up the current position to an alignment
+ * boundary.
+ */
+ if (isBinary)
+ {
+ int offset = res->curOffset % PGRESULT_ALIGN_BOUNDARY;
+
+ if (offset)
+ {
+ res->curOffset += PGRESULT_ALIGN_BOUNDARY - offset;
+ res->spaceLeft -= PGRESULT_ALIGN_BOUNDARY - offset;
+ }
+ }
+
+ /* If there's enough space in the current block, no problem. */
+ if (nBytes <= (size_t) res->spaceLeft)
+ {
+ space = res->curBlock->space + res->curOffset;
+ res->curOffset += nBytes;
+ res->spaceLeft -= nBytes;
+ return space;
+ }
+
+ /*
+ * If the requested object is very large, give it its own block; this
+ * avoids wasting what might be most of the current block to start a new
+ * block. (We'd have to special-case requests bigger than the block size
+ * anyway.) The object is always given binary alignment in this case.
+ */
+ if (nBytes >= PGRESULT_SEP_ALLOC_THRESHOLD)
+ {
+ size_t alloc_size = nBytes + PGRESULT_BLOCK_OVERHEAD;
+
+ block = (PGresult_data *) malloc(alloc_size);
+ if (!block)
+ return NULL;
+ res->memorySize += alloc_size;
+ space = block->space + PGRESULT_BLOCK_OVERHEAD;
+ if (res->curBlock)
+ {
+ /*
+ * Tuck special block below the active block, so that we don't
+ * have to waste the free space in the active block.
+ */
+ block->next = res->curBlock->next;
+ res->curBlock->next = block;
+ }
+ else
+ {
+ /* Must set up the new block as the first active block. */
+ block->next = NULL;
+ res->curBlock = block;
+ res->spaceLeft = 0; /* be sure it's marked full */
+ }
+ return space;
+ }
+
+ /* Otherwise, start a new block. */
+ block = (PGresult_data *) malloc(PGRESULT_DATA_BLOCKSIZE);
+ if (!block)
+ return NULL;
+ res->memorySize += PGRESULT_DATA_BLOCKSIZE;
+ block->next = res->curBlock;
+ res->curBlock = block;
+ if (isBinary)
+ {
+ /* object needs full alignment */
+ res->curOffset = PGRESULT_BLOCK_OVERHEAD;
+ res->spaceLeft = PGRESULT_DATA_BLOCKSIZE - PGRESULT_BLOCK_OVERHEAD;
+ }
+ else
+ {
+ /* we can cram it right after the overhead pointer */
+ res->curOffset = sizeof(PGresult_data);
+ res->spaceLeft = PGRESULT_DATA_BLOCKSIZE - sizeof(PGresult_data);
+ }
+
+ space = block->space + res->curOffset;
+ res->curOffset += nBytes;
+ res->spaceLeft -= nBytes;
+ return space;
+}
+
+/*
+ * PQresultMemorySize -
+ * Returns total space allocated for the PGresult.
+ */
+size_t
+PQresultMemorySize(const PGresult *res)
+{
+ if (!res)
+ return 0;
+ return res->memorySize;
+}
+
+/*
+ * pqResultStrdup -
+ * Like strdup, but the space is subsidiary PGresult space.
+ */
+char *
+pqResultStrdup(PGresult *res, const char *str)
+{
+ char *space = (char *) pqResultAlloc(res, strlen(str) + 1, false);
+
+ if (space)
+ strcpy(space, str);
+ return space;
+}
+
+/*
+ * pqSetResultError -
+ * assign a new error message to a PGresult
+ */
+void
+pqSetResultError(PGresult *res, PQExpBuffer errorMessage)
+{
+ char *msg;
+
+ if (!res)
+ return;
+
+ /*
+ * We handle two OOM scenarios here. The errorMessage buffer might be
+ * marked "broken" due to having previously failed to allocate enough
+ * memory for the message, or it might be fine but pqResultStrdup fails
+ * and returns NULL. In either case, just make res->errMsg point directly
+ * at a constant "out of memory" string.
+ */
+ if (!PQExpBufferBroken(errorMessage))
+ msg = pqResultStrdup(res, errorMessage->data);
+ else
+ msg = NULL;
+ if (msg)
+ res->errMsg = msg;
+ else
+ res->errMsg = libpq_gettext("out of memory\n");
+}
+
+/*
+ * PQclear -
+ * free's the memory associated with a PGresult
+ */
+void
+PQclear(PGresult *res)
+{
+ PGresult_data *block;
+ int i;
+
+ if (!res)
+ return;
+
+ for (i = 0; i < res->nEvents; i++)
+ {
+ /* only send DESTROY to successfully-initialized event procs */
+ if (res->events[i].resultInitialized)
+ {
+ PGEventResultDestroy evt;
+
+ evt.result = res;
+ (void) res->events[i].proc(PGEVT_RESULTDESTROY, &evt,
+ res->events[i].passThrough);
+ }
+ free(res->events[i].name);
+ }
+
+ if (res->events)
+ free(res->events);
+
+ /* Free all the subsidiary blocks */
+ while ((block = res->curBlock) != NULL)
+ {
+ res->curBlock = block->next;
+ free(block);
+ }
+
+ /* Free the top-level tuple pointer array */
+ if (res->tuples)
+ free(res->tuples);
+
+ /* zero out the pointer fields to catch programming errors */
+ res->attDescs = NULL;
+ res->tuples = NULL;
+ res->paramDescs = NULL;
+ res->errFields = NULL;
+ res->events = NULL;
+ res->nEvents = 0;
+ /* res->curBlock was zeroed out earlier */
+
+ /* Free the PGresult structure itself */
+ free(res);
+}
+
+/*
+ * Handy subroutine to deallocate any partially constructed async result.
+ *
+ * Any "next" result gets cleared too.
+ */
+void
+pqClearAsyncResult(PGconn *conn)
+{
+ if (conn->result)
+ PQclear(conn->result);
+ conn->result = NULL;
+ if (conn->next_result)
+ PQclear(conn->next_result);
+ conn->next_result = NULL;
+}
+
+/*
+ * This subroutine deletes any existing async result, sets conn->result
+ * to a PGresult with status PGRES_FATAL_ERROR, and stores the current
+ * contents of conn->errorMessage into that result.
+ */
+void
+pqSaveErrorResult(PGconn *conn)
+{
+ pqClearAsyncResult(conn);
+ conn->result = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
+}
+
+/*
+ * As above, after appending conn->write_err_msg to whatever other error we
+ * have. This is used when we've detected a write failure and have exhausted
+ * our chances of reporting something else instead.
+ */
+static void
+pqSaveWriteError(PGconn *conn)
+{
+ /*
+ * If write_err_msg is null because of previous strdup failure, do what we
+ * can. (It's likely our machinations here will get OOM failures as well,
+ * but might as well try.)
+ */
+ if (conn->write_err_msg)
+ {
+ appendPQExpBufferStr(&conn->errorMessage, conn->write_err_msg);
+ /* Avoid possibly appending the same message twice */
+ conn->write_err_msg[0] = '\0';
+ }
+ else
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("write to server failed\n"));
+
+ pqSaveErrorResult(conn);
+}
+
+/*
+ * This subroutine prepares an async result object for return to the caller.
+ * If there is not already an async result object, build an error object
+ * using whatever is in conn->errorMessage. In any case, clear the async
+ * result storage.
+ */
+PGresult *
+pqPrepareAsyncResult(PGconn *conn)
+{
+ PGresult *res;
+
+ /*
+ * conn->result is the PGresult to return. If it is NULL (which probably
+ * shouldn't happen) we assume there is an appropriate error message in
+ * conn->errorMessage.
+ */
+ res = conn->result;
+ if (!res)
+ res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
+
+ /*
+ * Replace conn->result with next_result, if any. In the normal case
+ * there isn't a next result and we're just dropping ownership of the
+ * current result. In single-row mode this restores the situation to what
+ * it was before we created the current single-row result.
+ */
+ conn->result = conn->next_result;
+ conn->next_result = NULL;
+
+ return res;
+}
+
+/*
+ * pqInternalNotice - produce an internally-generated notice message
+ *
+ * A format string and optional arguments can be passed. Note that we do
+ * libpq_gettext() here, so callers need not.
+ *
+ * The supplied text is taken as primary message (ie., it should not include
+ * a trailing newline, and should not be more than one line).
+ */
+void
+pqInternalNotice(const PGNoticeHooks *hooks, const char *fmt,...)
+{
+ char msgBuf[1024];
+ va_list args;
+ PGresult *res;
+
+ if (hooks->noticeRec == NULL)
+ return; /* nobody home to receive notice? */
+
+ /* Format the message */
+ va_start(args, fmt);
+ vsnprintf(msgBuf, sizeof(msgBuf), libpq_gettext(fmt), args);
+ va_end(args);
+ msgBuf[sizeof(msgBuf) - 1] = '\0'; /* make real sure it's terminated */
+
+ /* Make a PGresult to pass to the notice receiver */
+ res = PQmakeEmptyPGresult(NULL, PGRES_NONFATAL_ERROR);
+ if (!res)
+ return;
+ res->noticeHooks = *hooks;
+
+ /*
+ * Set up fields of notice.
+ */
+ pqSaveMessageField(res, PG_DIAG_MESSAGE_PRIMARY, msgBuf);
+ pqSaveMessageField(res, PG_DIAG_SEVERITY, libpq_gettext("NOTICE"));
+ pqSaveMessageField(res, PG_DIAG_SEVERITY_NONLOCALIZED, "NOTICE");
+ /* XXX should provide a SQLSTATE too? */
+
+ /*
+ * Result text is always just the primary message + newline. If we can't
+ * allocate it, substitute "out of memory", as in pqSetResultError.
+ */
+ res->errMsg = (char *) pqResultAlloc(res, strlen(msgBuf) + 2, false);
+ if (res->errMsg)
+ sprintf(res->errMsg, "%s\n", msgBuf);
+ else
+ res->errMsg = libpq_gettext("out of memory\n");
+
+ /*
+ * Pass to receiver, then free it.
+ */
+ res->noticeHooks.noticeRec(res->noticeHooks.noticeRecArg, res);
+ PQclear(res);
+}
+
+/*
+ * pqAddTuple
+ * add a row pointer to the PGresult structure, growing it if necessary
+ * Returns true if OK, false if an error prevented adding the row
+ *
+ * On error, *errmsgp can be set to an error string to be returned.
+ * If it is left NULL, the error is presumed to be "out of memory".
+ */
+static bool
+pqAddTuple(PGresult *res, PGresAttValue *tup, const char **errmsgp)
+{
+ if (res->ntups >= res->tupArrSize)
+ {
+ /*
+ * Try to grow the array.
+ *
+ * We can use realloc because shallow copying of the structure is
+ * okay. Note that the first time through, res->tuples is NULL. While
+ * ANSI says that realloc() should act like malloc() in that case,
+ * some old C libraries (like SunOS 4.1.x) coredump instead. On
+ * failure realloc is supposed to return NULL without damaging the
+ * existing allocation. Note that the positions beyond res->ntups are
+ * garbage, not necessarily NULL.
+ */
+ int newSize;
+ PGresAttValue **newTuples;
+
+ /*
+ * Since we use integers for row numbers, we can't support more than
+ * INT_MAX rows. Make sure we allow that many, though.
+ */
+ if (res->tupArrSize <= INT_MAX / 2)
+ newSize = (res->tupArrSize > 0) ? res->tupArrSize * 2 : 128;
+ else if (res->tupArrSize < INT_MAX)
+ newSize = INT_MAX;
+ else
+ {
+ *errmsgp = libpq_gettext("PGresult cannot support more than INT_MAX tuples");
+ return false;
+ }
+
+ /*
+ * Also, on 32-bit platforms we could, in theory, overflow size_t even
+ * before newSize gets to INT_MAX. (In practice we'd doubtless hit
+ * OOM long before that, but let's check.)
+ */
+#if INT_MAX >= (SIZE_MAX / 2)
+ if (newSize > SIZE_MAX / sizeof(PGresAttValue *))
+ {
+ *errmsgp = libpq_gettext("size_t overflow");
+ return false;
+ }
+#endif
+
+ if (res->tuples == NULL)
+ newTuples = (PGresAttValue **)
+ malloc(newSize * sizeof(PGresAttValue *));
+ else
+ newTuples = (PGresAttValue **)
+ realloc(res->tuples, newSize * sizeof(PGresAttValue *));
+ if (!newTuples)
+ return false; /* malloc or realloc failed */
+ res->memorySize +=
+ (newSize - res->tupArrSize) * sizeof(PGresAttValue *);
+ res->tupArrSize = newSize;
+ res->tuples = newTuples;
+ }
+ res->tuples[res->ntups] = tup;
+ res->ntups++;
+ return true;
+}
+
+/*
+ * pqSaveMessageField - save one field of an error or notice message
+ */
+void
+pqSaveMessageField(PGresult *res, char code, const char *value)
+{
+ PGMessageField *pfield;
+
+ pfield = (PGMessageField *)
+ pqResultAlloc(res,
+ offsetof(PGMessageField, contents) +
+ strlen(value) + 1,
+ true);
+ if (!pfield)
+ return; /* out of memory? */
+ pfield->code = code;
+ strcpy(pfield->contents, value);
+ pfield->next = res->errFields;
+ res->errFields = pfield;
+}
+
+/*
+ * pqSaveParameterStatus - remember parameter status sent by backend
+ */
+void
+pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
+{
+ pgParameterStatus *pstatus;
+ pgParameterStatus *prev;
+
+ /*
+ * Forget any old information about the parameter
+ */
+ for (pstatus = conn->pstatus, prev = NULL;
+ pstatus != NULL;
+ prev = pstatus, pstatus = pstatus->next)
+ {
+ if (strcmp(pstatus->name, name) == 0)
+ {
+ if (prev)
+ prev->next = pstatus->next;
+ else
+ conn->pstatus = pstatus->next;
+ free(pstatus); /* frees name and value strings too */
+ break;
+ }
+ }
+
+ /*
+ * Store new info as a single malloc block
+ */
+ pstatus = (pgParameterStatus *) malloc(sizeof(pgParameterStatus) +
+ strlen(name) + strlen(value) + 2);
+ if (pstatus)
+ {
+ char *ptr;
+
+ ptr = ((char *) pstatus) + sizeof(pgParameterStatus);
+ pstatus->name = ptr;
+ strcpy(ptr, name);
+ ptr += strlen(name) + 1;
+ pstatus->value = ptr;
+ strcpy(ptr, value);
+ pstatus->next = conn->pstatus;
+ conn->pstatus = pstatus;
+ }
+
+ /*
+ * Save values of settings that are of interest to libpq in fields of the
+ * PGconn object. We keep client_encoding and standard_conforming_strings
+ * in static variables as well, so that PQescapeString and PQescapeBytea
+ * can behave somewhat sanely (at least in single-connection-using
+ * programs).
+ */
+ if (strcmp(name, "client_encoding") == 0)
+ {
+ conn->client_encoding = pg_char_to_encoding(value);
+ /* if we don't recognize the encoding name, fall back to SQL_ASCII */
+ if (conn->client_encoding < 0)
+ conn->client_encoding = PG_SQL_ASCII;
+ static_client_encoding = conn->client_encoding;
+ }
+ else if (strcmp(name, "standard_conforming_strings") == 0)
+ {
+ conn->std_strings = (strcmp(value, "on") == 0);
+ static_std_strings = conn->std_strings;
+ }
+ else if (strcmp(name, "server_version") == 0)
+ {
+ /* We convert the server version to numeric form. */
+ int cnt;
+ int vmaj,
+ vmin,
+ vrev;
+
+ cnt = sscanf(value, "%d.%d.%d", &vmaj, &vmin, &vrev);
+
+ if (cnt == 3)
+ {
+ /* old style, e.g. 9.6.1 */
+ conn->sversion = (100 * vmaj + vmin) * 100 + vrev;
+ }
+ else if (cnt == 2)
+ {
+ if (vmaj >= 10)
+ {
+ /* new style, e.g. 10.1 */
+ conn->sversion = 100 * 100 * vmaj + vmin;
+ }
+ else
+ {
+ /* old style without minor version, e.g. 9.6devel */
+ conn->sversion = (100 * vmaj + vmin) * 100;
+ }
+ }
+ else if (cnt == 1)
+ {
+ /* new style without minor version, e.g. 10devel */
+ conn->sversion = 100 * 100 * vmaj;
+ }
+ else
+ conn->sversion = 0; /* unknown */
+ }
+ else if (strcmp(name, "default_transaction_read_only") == 0)
+ {
+ conn->default_transaction_read_only =
+ (strcmp(value, "on") == 0) ? PG_BOOL_YES : PG_BOOL_NO;
+ }
+ else if (strcmp(name, "in_hot_standby") == 0)
+ {
+ conn->in_hot_standby =
+ (strcmp(value, "on") == 0) ? PG_BOOL_YES : PG_BOOL_NO;
+ }
+}
+
+
+/*
+ * pqRowProcessor
+ * Add the received row to the current async result (conn->result).
+ * Returns 1 if OK, 0 if error occurred.
+ *
+ * On error, *errmsgp can be set to an error string to be returned.
+ * If it is left NULL, the error is presumed to be "out of memory".
+ *
+ * In single-row mode, we create a new result holding just the current row,
+ * stashing the previous result in conn->next_result so that it becomes
+ * active again after pqPrepareAsyncResult(). This allows the result metadata
+ * (column descriptions) to be carried forward to each result row.
+ */
+int
+pqRowProcessor(PGconn *conn, const char **errmsgp)
+{
+ PGresult *res = conn->result;
+ int nfields = res->numAttributes;
+ const PGdataValue *columns = conn->rowBuf;
+ PGresAttValue *tup;
+ int i;
+
+ /*
+ * In single-row mode, make a new PGresult that will hold just this one
+ * row; the original conn->result is left unchanged so that it can be used
+ * again as the template for future rows.
+ */
+ if (conn->singleRowMode)
+ {
+ /* Copy everything that should be in the result at this point */
+ res = PQcopyResult(res,
+ PG_COPYRES_ATTRS | PG_COPYRES_EVENTS |
+ PG_COPYRES_NOTICEHOOKS);
+ if (!res)
+ return 0;
+ }
+
+ /*
+ * Basically we just allocate space in the PGresult for each field and
+ * copy the data over.
+ *
+ * Note: on malloc failure, we return 0 leaving *errmsgp still NULL, which
+ * caller will take to mean "out of memory". This is preferable to trying
+ * to set up such a message here, because evidently there's not enough
+ * memory for gettext() to do anything.
+ */
+ tup = (PGresAttValue *)
+ pqResultAlloc(res, nfields * sizeof(PGresAttValue), true);
+ if (tup == NULL)
+ goto fail;
+
+ for (i = 0; i < nfields; i++)
+ {
+ int clen = columns[i].len;
+
+ if (clen < 0)
+ {
+ /* null field */
+ tup[i].len = NULL_LEN;
+ tup[i].value = res->null_field;
+ }
+ else
+ {
+ bool isbinary = (res->attDescs[i].format != 0);
+ char *val;
+
+ val = (char *) pqResultAlloc(res, clen + 1, isbinary);
+ if (val == NULL)
+ goto fail;
+
+ /* copy and zero-terminate the data (even if it's binary) */
+ memcpy(val, columns[i].value, clen);
+ val[clen] = '\0';
+
+ tup[i].len = clen;
+ tup[i].value = val;
+ }
+ }
+
+ /* And add the tuple to the PGresult's tuple array */
+ if (!pqAddTuple(res, tup, errmsgp))
+ goto fail;
+
+ /*
+ * Success. In single-row mode, make the result available to the client
+ * immediately.
+ */
+ if (conn->singleRowMode)
+ {
+ /* Change result status to special single-row value */
+ res->resultStatus = PGRES_SINGLE_TUPLE;
+ /* Stash old result for re-use later */
+ conn->next_result = conn->result;
+ conn->result = res;
+ /* And mark the result ready to return */
+ conn->asyncStatus = PGASYNC_READY_MORE;
+ }
+
+ return 1;
+
+fail:
+ /* release locally allocated PGresult, if we made one */
+ if (res != conn->result)
+ PQclear(res);
+ return 0;
+}
+
+
+/*
+ * pqAllocCmdQueueEntry
+ * Get a command queue entry for caller to fill.
+ *
+ * If the recycle queue has a free element, that is returned; if not, a
+ * fresh one is allocated. Caller is responsible for adding it to the
+ * command queue (pqAppendCmdQueueEntry) once the struct is filled in, or
+ * releasing the memory (pqRecycleCmdQueueEntry) if an error occurs.
+ *
+ * If allocation fails, sets the error message and returns NULL.
+ */
+static PGcmdQueueEntry *
+pqAllocCmdQueueEntry(PGconn *conn)
+{
+ PGcmdQueueEntry *entry;
+
+ if (conn->cmd_queue_recycle == NULL)
+ {
+ entry = (PGcmdQueueEntry *) malloc(sizeof(PGcmdQueueEntry));
+ if (entry == NULL)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("out of memory\n"));
+ return NULL;
+ }
+ }
+ else
+ {
+ entry = conn->cmd_queue_recycle;
+ conn->cmd_queue_recycle = entry->next;
+ }
+ entry->next = NULL;
+ entry->query = NULL;
+
+ return entry;
+}
+
+/*
+ * pqAppendCmdQueueEntry
+ * Append a caller-allocated entry to the command queue, and update
+ * conn->asyncStatus to account for it.
+ *
+ * The query itself must already have been put in the output buffer by the
+ * caller.
+ */
+static void
+pqAppendCmdQueueEntry(PGconn *conn, PGcmdQueueEntry *entry)
+{
+ Assert(entry->next == NULL);
+
+ if (conn->cmd_queue_head == NULL)
+ conn->cmd_queue_head = entry;
+ else
+ conn->cmd_queue_tail->next = entry;
+
+ conn->cmd_queue_tail = entry;
+
+ switch (conn->pipelineStatus)
+ {
+ case PQ_PIPELINE_OFF:
+ case PQ_PIPELINE_ON:
+
+ /*
+ * When not in pipeline aborted state, if there's a result ready
+ * to be consumed, let it be so (that is, don't change away from
+ * READY or READY_MORE); otherwise set us busy to wait for
+ * something to arrive from the server.
+ */
+ if (conn->asyncStatus == PGASYNC_IDLE)
+ conn->asyncStatus = PGASYNC_BUSY;
+ break;
+
+ case PQ_PIPELINE_ABORTED:
+
+ /*
+ * In aborted pipeline state, we don't expect anything from the
+ * server (since we don't send any queries that are queued).
+ * Therefore, if IDLE then do what PQgetResult would do to let
+ * itself consume commands from the queue; if we're in any other
+ * state, we don't have to do anything.
+ */
+ if (conn->asyncStatus == PGASYNC_IDLE ||
+ conn->asyncStatus == PGASYNC_PIPELINE_IDLE)
+ {
+ resetPQExpBuffer(&conn->errorMessage);
+ pqPipelineProcessQueue(conn);
+ }
+ break;
+ }
+}
+
+/*
+ * pqRecycleCmdQueueEntry
+ * Push a command queue entry onto the freelist.
+ */
+static void
+pqRecycleCmdQueueEntry(PGconn *conn, PGcmdQueueEntry *entry)
+{
+ if (entry == NULL)
+ return;
+
+ /* recyclable entries should not have a follow-on command */
+ Assert(entry->next == NULL);
+
+ if (entry->query)
+ {
+ free(entry->query);
+ entry->query = NULL;
+ }
+
+ entry->next = conn->cmd_queue_recycle;
+ conn->cmd_queue_recycle = entry;
+}
+
+
+/*
+ * PQsendQuery
+ * Submit a query, but don't wait for it to finish
+ *
+ * Returns: 1 if successfully submitted
+ * 0 if error (conn->errorMessage is set)
+ *
+ * PQsendQueryContinue is a non-exported version that behaves identically
+ * except that it doesn't reset conn->errorMessage.
+ */
+int
+PQsendQuery(PGconn *conn, const char *query)
+{
+ return PQsendQueryInternal(conn, query, true);
+}
+
+int
+PQsendQueryContinue(PGconn *conn, const char *query)
+{
+ return PQsendQueryInternal(conn, query, false);
+}
+
+static int
+PQsendQueryInternal(PGconn *conn, const char *query, bool newQuery)
+{
+ PGcmdQueueEntry *entry = NULL;
+ PGcmdQueueEntry *entry2 = NULL;
+
+ if (!PQsendQueryStart(conn, newQuery))
+ return 0;
+
+ /* check the argument */
+ if (!query)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("command string is a null pointer\n"));
+ return 0;
+ }
+
+ entry = pqAllocCmdQueueEntry(conn);
+ if (entry == NULL)
+ return 0; /* error msg already set */
+ if (conn->pipelineStatus != PQ_PIPELINE_OFF)
+ {
+ entry2 = pqAllocCmdQueueEntry(conn);
+ if (entry2 == NULL)
+ goto sendFailed;
+ }
+
+ /* Send the query message(s) */
+ if (conn->pipelineStatus == PQ_PIPELINE_OFF)
+ {
+ /* construct the outgoing Query message */
+ if (pqPutMsgStart('Q', conn) < 0 ||
+ pqPuts(query, conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ {
+ /* error message should be set up already */
+ pqRecycleCmdQueueEntry(conn, entry);
+ return 0;
+ }
+
+ /* remember we are using simple query protocol */
+ entry->queryclass = PGQUERY_SIMPLE;
+ /* and remember the query text too, if possible */
+ entry->query = strdup(query);
+ }
+ else
+ {
+ /*
+ * In pipeline mode we cannot use the simple protocol, so we send
+ * Parse, Bind, Describe Portal, Execute, Close Portal (with the
+ * unnamed portal).
+ */
+ if (pqPutMsgStart('P', conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPuts(query, conn) < 0 ||
+ pqPutInt(0, 2, conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+ if (pqPutMsgStart('B', conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPutInt(0, 2, conn) < 0 ||
+ pqPutInt(0, 2, conn) < 0 ||
+ pqPutInt(0, 2, conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+ if (pqPutMsgStart('D', conn) < 0 ||
+ pqPutc('P', conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+ if (pqPutMsgStart('E', conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPutInt(0, 4, conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+ if (pqPutMsgStart('C', conn) < 0 ||
+ pqPutc('P', conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+
+ entry->queryclass = PGQUERY_EXTENDED;
+ entry->query = strdup(query);
+ }
+
+ /*
+ * Give the data a push. In nonblock mode, don't complain if we're unable
+ * to send it all; PQgetResult() will do any additional flushing needed.
+ */
+ if (pqPipelineFlush(conn) < 0)
+ goto sendFailed;
+
+ /* OK, it's launched! */
+ pqAppendCmdQueueEntry(conn, entry);
+
+ /*
+ * When pipeline mode is in use, we need a second entry in the command
+ * queue to represent Close Portal message. This allows us later to wait
+ * for the CloseComplete message to be received before getting in IDLE
+ * state.
+ */
+ if (conn->pipelineStatus != PQ_PIPELINE_OFF)
+ {
+ entry2->queryclass = PGQUERY_CLOSE;
+ entry2->query = NULL;
+ pqAppendCmdQueueEntry(conn, entry2);
+ }
+
+ return 1;
+
+sendFailed:
+ pqRecycleCmdQueueEntry(conn, entry);
+ pqRecycleCmdQueueEntry(conn, entry2);
+ /* error message should be set up already */
+ return 0;
+}
+
+/*
+ * PQsendQueryParams
+ * Like PQsendQuery, but use extended query protocol so we can pass parameters
+ */
+int
+PQsendQueryParams(PGconn *conn,
+ const char *command,
+ int nParams,
+ const Oid *paramTypes,
+ const char *const *paramValues,
+ const int *paramLengths,
+ const int *paramFormats,
+ int resultFormat)
+{
+ if (!PQsendQueryStart(conn, true))
+ return 0;
+
+ /* check the arguments */
+ if (!command)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("command string is a null pointer\n"));
+ return 0;
+ }
+ if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
+ {
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("number of parameters must be between 0 and %d\n"),
+ PQ_QUERY_PARAM_MAX_LIMIT);
+ return 0;
+ }
+
+ return PQsendQueryGuts(conn,
+ command,
+ "", /* use unnamed statement */
+ nParams,
+ paramTypes,
+ paramValues,
+ paramLengths,
+ paramFormats,
+ resultFormat);
+}
+
+/*
+ * PQsendPrepare
+ * Submit a Parse message, but don't wait for it to finish
+ *
+ * Returns: 1 if successfully submitted
+ * 0 if error (conn->errorMessage is set)
+ */
+int
+PQsendPrepare(PGconn *conn,
+ const char *stmtName, const char *query,
+ int nParams, const Oid *paramTypes)
+{
+ PGcmdQueueEntry *entry = NULL;
+
+ if (!PQsendQueryStart(conn, true))
+ return 0;
+
+ /* check the arguments */
+ if (!stmtName)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("statement name is a null pointer\n"));
+ return 0;
+ }
+ if (!query)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("command string is a null pointer\n"));
+ return 0;
+ }
+ if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
+ {
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("number of parameters must be between 0 and %d\n"),
+ PQ_QUERY_PARAM_MAX_LIMIT);
+ return 0;
+ }
+
+ entry = pqAllocCmdQueueEntry(conn);
+ if (entry == NULL)
+ return 0; /* error msg already set */
+
+ /* construct the Parse message */
+ if (pqPutMsgStart('P', conn) < 0 ||
+ pqPuts(stmtName, conn) < 0 ||
+ pqPuts(query, conn) < 0)
+ goto sendFailed;
+
+ if (nParams > 0 && paramTypes)
+ {
+ int i;
+
+ if (pqPutInt(nParams, 2, conn) < 0)
+ goto sendFailed;
+ for (i = 0; i < nParams; i++)
+ {
+ if (pqPutInt(paramTypes[i], 4, conn) < 0)
+ goto sendFailed;
+ }
+ }
+ else
+ {
+ if (pqPutInt(0, 2, conn) < 0)
+ goto sendFailed;
+ }
+ if (pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+
+ /* Add a Sync, unless in pipeline mode. */
+ if (conn->pipelineStatus == PQ_PIPELINE_OFF)
+ {
+ if (pqPutMsgStart('S', conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+ }
+
+ /* remember we are doing just a Parse */
+ entry->queryclass = PGQUERY_PREPARE;
+
+ /* and remember the query text too, if possible */
+ /* if insufficient memory, query just winds up NULL */
+ entry->query = strdup(query);
+
+ /*
+ * Give the data a push (in pipeline mode, only if we're past the size
+ * threshold). In nonblock mode, don't complain if we're unable to send
+ * it all; PQgetResult() will do any additional flushing needed.
+ */
+ if (pqPipelineFlush(conn) < 0)
+ goto sendFailed;
+
+ /* OK, it's launched! */
+ pqAppendCmdQueueEntry(conn, entry);
+
+ return 1;
+
+sendFailed:
+ pqRecycleCmdQueueEntry(conn, entry);
+ /* error message should be set up already */
+ return 0;
+}
+
+/*
+ * PQsendQueryPrepared
+ * Like PQsendQuery, but execute a previously prepared statement,
+ * using extended query protocol so we can pass parameters
+ */
+int
+PQsendQueryPrepared(PGconn *conn,
+ const char *stmtName,
+ int nParams,
+ const char *const *paramValues,
+ const int *paramLengths,
+ const int *paramFormats,
+ int resultFormat)
+{
+ if (!PQsendQueryStart(conn, true))
+ return 0;
+
+ /* check the arguments */
+ if (!stmtName)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("statement name is a null pointer\n"));
+ return 0;
+ }
+ if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
+ {
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("number of parameters must be between 0 and %d\n"),
+ PQ_QUERY_PARAM_MAX_LIMIT);
+ return 0;
+ }
+
+ return PQsendQueryGuts(conn,
+ NULL, /* no command to parse */
+ stmtName,
+ nParams,
+ NULL, /* no param types */
+ paramValues,
+ paramLengths,
+ paramFormats,
+ resultFormat);
+}
+
+/*
+ * PQsendQueryStart
+ * Common startup code for PQsendQuery and sibling routines
+ */
+static bool
+PQsendQueryStart(PGconn *conn, bool newQuery)
+{
+ if (!conn)
+ return false;
+
+ /*
+ * If this is the beginning of a query cycle, reset the error buffer.
+ */
+ if (newQuery)
+ resetPQExpBuffer(&conn->errorMessage);
+
+ /* Don't try to send if we know there's no live connection. */
+ if (conn->status != CONNECTION_OK)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("no connection to the server\n"));
+ return false;
+ }
+
+ /* Can't send while already busy, either, unless enqueuing for later */
+ if (conn->asyncStatus != PGASYNC_IDLE &&
+ conn->pipelineStatus == PQ_PIPELINE_OFF)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("another command is already in progress\n"));
+ return false;
+ }
+
+ if (conn->pipelineStatus != PQ_PIPELINE_OFF)
+ {
+ /*
+ * When enqueuing commands we don't change much of the connection
+ * state since it's already in use for the current command. The
+ * connection state will get updated when pqPipelineProcessQueue()
+ * advances to start processing the queued message.
+ *
+ * Just make sure we can safely enqueue given the current connection
+ * state. We can enqueue behind another queue item, or behind a
+ * non-queue command (one that sends its own sync), but we can't
+ * enqueue if the connection is in a copy state.
+ */
+ switch (conn->asyncStatus)
+ {
+ case PGASYNC_IDLE:
+ case PGASYNC_PIPELINE_IDLE:
+ case PGASYNC_READY:
+ case PGASYNC_READY_MORE:
+ case PGASYNC_BUSY:
+ /* ok to queue */
+ break;
+
+ case PGASYNC_COPY_IN:
+ case PGASYNC_COPY_OUT:
+ case PGASYNC_COPY_BOTH:
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("cannot queue commands during COPY\n"));
+ return false;
+ }
+ }
+ else
+ {
+ /*
+ * This command's results will come in immediately. Initialize async
+ * result-accumulation state
+ */
+ pqClearAsyncResult(conn);
+
+ /* reset single-row processing mode */
+ conn->singleRowMode = false;
+
+ }
+ /* ready to send command message */
+ return true;
+}
+
+/*
+ * PQsendQueryGuts
+ * Common code for sending a query with extended query protocol
+ * PQsendQueryStart should be done already
+ *
+ * command may be NULL to indicate we use an already-prepared statement
+ */
+static int
+PQsendQueryGuts(PGconn *conn,
+ const char *command,
+ const char *stmtName,
+ int nParams,
+ const Oid *paramTypes,
+ const char *const *paramValues,
+ const int *paramLengths,
+ const int *paramFormats,
+ int resultFormat)
+{
+ int i;
+ PGcmdQueueEntry *entry;
+
+ entry = pqAllocCmdQueueEntry(conn);
+ if (entry == NULL)
+ return 0; /* error msg already set */
+
+ /*
+ * We will send Parse (if needed), Bind, Describe Portal, Execute, Sync
+ * (if not in pipeline mode), using specified statement name and the
+ * unnamed portal.
+ */
+
+ if (command)
+ {
+ /* construct the Parse message */
+ if (pqPutMsgStart('P', conn) < 0 ||
+ pqPuts(stmtName, conn) < 0 ||
+ pqPuts(command, conn) < 0)
+ goto sendFailed;
+ if (nParams > 0 && paramTypes)
+ {
+ if (pqPutInt(nParams, 2, conn) < 0)
+ goto sendFailed;
+ for (i = 0; i < nParams; i++)
+ {
+ if (pqPutInt(paramTypes[i], 4, conn) < 0)
+ goto sendFailed;
+ }
+ }
+ else
+ {
+ if (pqPutInt(0, 2, conn) < 0)
+ goto sendFailed;
+ }
+ if (pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+ }
+
+ /* Construct the Bind message */
+ if (pqPutMsgStart('B', conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPuts(stmtName, conn) < 0)
+ goto sendFailed;
+
+ /* Send parameter formats */
+ if (nParams > 0 && paramFormats)
+ {
+ if (pqPutInt(nParams, 2, conn) < 0)
+ goto sendFailed;
+ for (i = 0; i < nParams; i++)
+ {
+ if (pqPutInt(paramFormats[i], 2, conn) < 0)
+ goto sendFailed;
+ }
+ }
+ else
+ {
+ if (pqPutInt(0, 2, conn) < 0)
+ goto sendFailed;
+ }
+
+ if (pqPutInt(nParams, 2, conn) < 0)
+ goto sendFailed;
+
+ /* Send parameters */
+ for (i = 0; i < nParams; i++)
+ {
+ if (paramValues && paramValues[i])
+ {
+ int nbytes;
+
+ if (paramFormats && paramFormats[i] != 0)
+ {
+ /* binary parameter */
+ if (paramLengths)
+ nbytes = paramLengths[i];
+ else
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("length must be given for binary parameter\n"));
+ goto sendFailed;
+ }
+ }
+ else
+ {
+ /* text parameter, do not use paramLengths */
+ nbytes = strlen(paramValues[i]);
+ }
+ if (pqPutInt(nbytes, 4, conn) < 0 ||
+ pqPutnchar(paramValues[i], nbytes, conn) < 0)
+ goto sendFailed;
+ }
+ else
+ {
+ /* take the param as NULL */
+ if (pqPutInt(-1, 4, conn) < 0)
+ goto sendFailed;
+ }
+ }
+ if (pqPutInt(1, 2, conn) < 0 ||
+ pqPutInt(resultFormat, 2, conn))
+ goto sendFailed;
+ if (pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+
+ /* construct the Describe Portal message */
+ if (pqPutMsgStart('D', conn) < 0 ||
+ pqPutc('P', conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+
+ /* construct the Execute message */
+ if (pqPutMsgStart('E', conn) < 0 ||
+ pqPuts("", conn) < 0 ||
+ pqPutInt(0, 4, conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+
+ /* construct the Sync message if not in pipeline mode */
+ if (conn->pipelineStatus == PQ_PIPELINE_OFF)
+ {
+ if (pqPutMsgStart('S', conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+ }
+
+ /* remember we are using extended query protocol */
+ entry->queryclass = PGQUERY_EXTENDED;
+
+ /* and remember the query text too, if possible */
+ /* if insufficient memory, query just winds up NULL */
+ if (command)
+ entry->query = strdup(command);
+
+ /*
+ * Give the data a push (in pipeline mode, only if we're past the size
+ * threshold). In nonblock mode, don't complain if we're unable to send
+ * it all; PQgetResult() will do any additional flushing needed.
+ */
+ if (pqPipelineFlush(conn) < 0)
+ goto sendFailed;
+
+ /* OK, it's launched! */
+ pqAppendCmdQueueEntry(conn, entry);
+
+ return 1;
+
+sendFailed:
+ pqRecycleCmdQueueEntry(conn, entry);
+ /* error message should be set up already */
+ return 0;
+}
+
+/*
+ * Select row-by-row processing mode
+ */
+int
+PQsetSingleRowMode(PGconn *conn)
+{
+ /*
+ * Only allow setting the flag when we have launched a query and not yet
+ * received any results.
+ */
+ if (!conn)
+ return 0;
+ if (conn->asyncStatus != PGASYNC_BUSY)
+ return 0;
+ if (!conn->cmd_queue_head ||
+ (conn->cmd_queue_head->queryclass != PGQUERY_SIMPLE &&
+ conn->cmd_queue_head->queryclass != PGQUERY_EXTENDED))
+ return 0;
+ if (conn->result)
+ return 0;
+
+ /* OK, set flag */
+ conn->singleRowMode = true;
+ return 1;
+}
+
+/*
+ * Consume any available input from the backend
+ * 0 return: some kind of trouble
+ * 1 return: no problem
+ */
+int
+PQconsumeInput(PGconn *conn)
+{
+ if (!conn)
+ return 0;
+
+ /*
+ * for non-blocking connections try to flush the send-queue, otherwise we
+ * may never get a response for something that may not have already been
+ * sent because it's in our write buffer!
+ */
+ if (pqIsnonblocking(conn))
+ {
+ if (pqFlush(conn) < 0)
+ return 0;
+ }
+
+ /*
+ * Load more data, if available. We do this no matter what state we are
+ * in, since we are probably getting called because the application wants
+ * to get rid of a read-select condition. Note that we will NOT block
+ * waiting for more input.
+ */
+ if (pqReadData(conn) < 0)
+ return 0;
+
+ /* Parsing of the data waits till later. */
+ return 1;
+}
+
+
+/*
+ * parseInput: if appropriate, parse input data from backend
+ * until input is exhausted or a stopping state is reached.
+ * Note that this function will NOT attempt to read more data from the backend.
+ */
+static void
+parseInput(PGconn *conn)
+{
+ pqParseInput3(conn);
+}
+
+/*
+ * PQisBusy
+ * Return true if PQgetResult would block waiting for input.
+ */
+
+int
+PQisBusy(PGconn *conn)
+{
+ if (!conn)
+ return false;
+
+ /* Parse any available data, if our state permits. */
+ parseInput(conn);
+
+ /*
+ * PQgetResult will return immediately in all states except BUSY. Also,
+ * if we've detected read EOF and dropped the connection, we can expect
+ * that PQgetResult will fail immediately. Note that we do *not* check
+ * conn->write_failed here --- once that's become set, we know we have
+ * trouble, but we need to keep trying to read until we have a complete
+ * server message or detect read EOF.
+ */
+ return conn->asyncStatus == PGASYNC_BUSY && conn->status != CONNECTION_BAD;
+}
+
+/*
+ * PQgetResult
+ * Get the next PGresult produced by a query. Returns NULL if no
+ * query work remains or an error has occurred (e.g. out of
+ * memory).
+ *
+ * In pipeline mode, once all the result of a query have been returned,
+ * PQgetResult returns NULL to let the user know that the next
+ * query is being processed. At the end of the pipeline, returns a
+ * result with PQresultStatus(result) == PGRES_PIPELINE_SYNC.
+ */
+PGresult *
+PQgetResult(PGconn *conn)
+{
+ PGresult *res;
+
+ if (!conn)
+ return NULL;
+
+ /* Parse any available data, if our state permits. */
+ parseInput(conn);
+
+ /* If not ready to return something, block until we are. */
+ while (conn->asyncStatus == PGASYNC_BUSY)
+ {
+ int flushResult;
+
+ /*
+ * If data remains unsent, send it. Else we might be waiting for the
+ * result of a command the backend hasn't even got yet.
+ */
+ while ((flushResult = pqFlush(conn)) > 0)
+ {
+ if (pqWait(false, true, conn))
+ {
+ flushResult = -1;
+ break;
+ }
+ }
+
+ /*
+ * Wait for some more data, and load it. (Note: if the connection has
+ * been lost, pqWait should return immediately because the socket
+ * should be read-ready, either with the last server data or with an
+ * EOF indication. We expect therefore that this won't result in any
+ * undue delay in reporting a previous write failure.)
+ */
+ if (flushResult ||
+ pqWait(true, false, conn) ||
+ pqReadData(conn) < 0)
+ {
+ /*
+ * conn->errorMessage has been set by pqWait or pqReadData. We
+ * want to append it to any already-received error message.
+ */
+ pqSaveErrorResult(conn);
+ conn->asyncStatus = PGASYNC_IDLE;
+ return pqPrepareAsyncResult(conn);
+ }
+
+ /* Parse it. */
+ parseInput(conn);
+
+ /*
+ * If we had a write error, but nothing above obtained a query result
+ * or detected a read error, report the write error.
+ */
+ if (conn->write_failed && conn->asyncStatus == PGASYNC_BUSY)
+ {
+ pqSaveWriteError(conn);
+ conn->asyncStatus = PGASYNC_IDLE;
+ return pqPrepareAsyncResult(conn);
+ }
+ }
+
+ /* Return the appropriate thing. */
+ switch (conn->asyncStatus)
+ {
+ case PGASYNC_IDLE:
+ res = NULL; /* query is complete */
+ break;
+ case PGASYNC_PIPELINE_IDLE:
+ Assert(conn->pipelineStatus != PQ_PIPELINE_OFF);
+
+ /*
+ * We're about to return the NULL that terminates the round of
+ * results from the current query; prepare to send the results
+ * of the next query, if any, when we're called next. If there's
+ * no next element in the command queue, this gets us in IDLE
+ * state.
+ */
+ resetPQExpBuffer(&conn->errorMessage);
+ pqPipelineProcessQueue(conn);
+ res = NULL; /* query is complete */
+ break;
+
+ case PGASYNC_READY:
+
+ /*
+ * For any query type other than simple query protocol, we advance
+ * the command queue here. This is because for simple query
+ * protocol we can get the READY state multiple times before the
+ * command is actually complete, since the command string can
+ * contain many queries. In simple query protocol, the queue
+ * advance is done by fe-protocol3 when it receives ReadyForQuery.
+ */
+ if (conn->cmd_queue_head &&
+ conn->cmd_queue_head->queryclass != PGQUERY_SIMPLE)
+ pqCommandQueueAdvance(conn);
+ res = pqPrepareAsyncResult(conn);
+ if (conn->pipelineStatus != PQ_PIPELINE_OFF)
+ {
+ /*
+ * We're about to send the results of the current query. Set
+ * us idle now, and ...
+ */
+ conn->asyncStatus = PGASYNC_PIPELINE_IDLE;
+
+ /*
+ * ... in cases when we're sending a pipeline-sync result,
+ * move queue processing forwards immediately, so that next
+ * time we're called, we're prepared to return the next result
+ * received from the server. In all other cases, leave the
+ * queue state change for next time, so that a terminating
+ * NULL result is sent.
+ *
+ * (In other words: we don't return a NULL after a pipeline
+ * sync.)
+ */
+ if (res && res->resultStatus == PGRES_PIPELINE_SYNC)
+ pqPipelineProcessQueue(conn);
+ }
+ else
+ {
+ /* Set the state back to BUSY, allowing parsing to proceed. */
+ conn->asyncStatus = PGASYNC_BUSY;
+ }
+ break;
+ case PGASYNC_READY_MORE:
+ res = pqPrepareAsyncResult(conn);
+ /* Set the state back to BUSY, allowing parsing to proceed. */
+ conn->asyncStatus = PGASYNC_BUSY;
+ break;
+ case PGASYNC_COPY_IN:
+ res = getCopyResult(conn, PGRES_COPY_IN);
+ break;
+ case PGASYNC_COPY_OUT:
+ res = getCopyResult(conn, PGRES_COPY_OUT);
+ break;
+ case PGASYNC_COPY_BOTH:
+ res = getCopyResult(conn, PGRES_COPY_BOTH);
+ break;
+ default:
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("unexpected asyncStatus: %d\n"),
+ (int) conn->asyncStatus);
+ res = PQmakeEmptyPGresult(conn, PGRES_FATAL_ERROR);
+ break;
+ }
+
+ /* If the next command we expect is CLOSE, read and consume it */
+ if (conn->asyncStatus == PGASYNC_PIPELINE_IDLE &&
+ conn->cmd_queue_head &&
+ conn->cmd_queue_head->queryclass == PGQUERY_CLOSE)
+ {
+ if (res && res->resultStatus != PGRES_FATAL_ERROR)
+ {
+ conn->asyncStatus = PGASYNC_BUSY;
+ parseInput(conn);
+ conn->asyncStatus = PGASYNC_PIPELINE_IDLE;
+ }
+ else
+ /* we won't ever see the Close */
+ pqCommandQueueAdvance(conn);
+ }
+
+ if (res)
+ {
+ int i;
+
+ for (i = 0; i < res->nEvents; i++)
+ {
+ PGEventResultCreate evt;
+
+ evt.conn = conn;
+ evt.result = res;
+ if (!res->events[i].proc(PGEVT_RESULTCREATE, &evt,
+ res->events[i].passThrough))
+ {
+ appendPQExpBuffer(&conn->errorMessage,
+ libpq_gettext("PGEventProc \"%s\" failed during PGEVT_RESULTCREATE event\n"),
+ res->events[i].name);
+ pqSetResultError(res, &conn->errorMessage);
+ res->resultStatus = PGRES_FATAL_ERROR;
+ break;
+ }
+ res->events[i].resultInitialized = true;
+ }
+ }
+
+ return res;
+}
+
+/*
+ * getCopyResult
+ * Helper for PQgetResult: generate result for COPY-in-progress cases
+ */
+static PGresult *
+getCopyResult(PGconn *conn, ExecStatusType copytype)
+{
+ /*
+ * If the server connection has been lost, don't pretend everything is
+ * hunky-dory; instead return a PGRES_FATAL_ERROR result, and reset the
+ * asyncStatus to idle (corresponding to what we'd do if we'd detected I/O
+ * error in the earlier steps in PQgetResult). The text returned in the
+ * result is whatever is in conn->errorMessage; we hope that was filled
+ * with something relevant when the lost connection was detected.
+ */
+ if (conn->status != CONNECTION_OK)
+ {
+ pqSaveErrorResult(conn);
+ conn->asyncStatus = PGASYNC_IDLE;
+ return pqPrepareAsyncResult(conn);
+ }
+
+ /* If we have an async result for the COPY, return that */
+ if (conn->result && conn->result->resultStatus == copytype)
+ return pqPrepareAsyncResult(conn);
+
+ /* Otherwise, invent a suitable PGresult */
+ return PQmakeEmptyPGresult(conn, copytype);
+}
+
+
+/*
+ * PQexec
+ * send a query to the backend and package up the result in a PGresult
+ *
+ * If the query was not even sent, return NULL; conn->errorMessage is set to
+ * a relevant message.
+ * If the query was sent, a new PGresult is returned (which could indicate
+ * either success or failure).
+ * The user is responsible for freeing the PGresult via PQclear()
+ * when done with it.
+ */
+PGresult *
+PQexec(PGconn *conn, const char *query)
+{
+ if (!PQexecStart(conn))
+ return NULL;
+ if (!PQsendQuery(conn, query))
+ return NULL;
+ return PQexecFinish(conn);
+}
+
+/*
+ * PQexecParams
+ * Like PQexec, but use extended query protocol so we can pass parameters
+ */
+PGresult *
+PQexecParams(PGconn *conn,
+ const char *command,
+ int nParams,
+ const Oid *paramTypes,
+ const char *const *paramValues,
+ const int *paramLengths,
+ const int *paramFormats,
+ int resultFormat)
+{
+ if (!PQexecStart(conn))
+ return NULL;
+ if (!PQsendQueryParams(conn, command,
+ nParams, paramTypes, paramValues, paramLengths,
+ paramFormats, resultFormat))
+ return NULL;
+ return PQexecFinish(conn);
+}
+
+/*
+ * PQprepare
+ * Creates a prepared statement by issuing a Parse message.
+ *
+ * If the query was not even sent, return NULL; conn->errorMessage is set to
+ * a relevant message.
+ * If the query was sent, a new PGresult is returned (which could indicate
+ * either success or failure).
+ * The user is responsible for freeing the PGresult via PQclear()
+ * when done with it.
+ */
+PGresult *
+PQprepare(PGconn *conn,
+ const char *stmtName, const char *query,
+ int nParams, const Oid *paramTypes)
+{
+ if (!PQexecStart(conn))
+ return NULL;
+ if (!PQsendPrepare(conn, stmtName, query, nParams, paramTypes))
+ return NULL;
+ return PQexecFinish(conn);
+}
+
+/*
+ * PQexecPrepared
+ * Like PQexec, but execute a previously prepared statement,
+ * using extended query protocol so we can pass parameters
+ */
+PGresult *
+PQexecPrepared(PGconn *conn,
+ const char *stmtName,
+ int nParams,
+ const char *const *paramValues,
+ const int *paramLengths,
+ const int *paramFormats,
+ int resultFormat)
+{
+ if (!PQexecStart(conn))
+ return NULL;
+ if (!PQsendQueryPrepared(conn, stmtName,
+ nParams, paramValues, paramLengths,
+ paramFormats, resultFormat))
+ return NULL;
+ return PQexecFinish(conn);
+}
+
+/*
+ * Common code for PQexec and sibling routines: prepare to send command
+ */
+static bool
+PQexecStart(PGconn *conn)
+{
+ PGresult *result;
+
+ if (!conn)
+ return false;
+
+ if (conn->pipelineStatus != PQ_PIPELINE_OFF)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("synchronous command execution functions are not allowed in pipeline mode\n"));
+ return false;
+ }
+
+ /*
+ * Since this is the beginning of a query cycle, reset the error buffer.
+ */
+ resetPQExpBuffer(&conn->errorMessage);
+
+ /*
+ * Silently discard any prior query result that application didn't eat.
+ * This is probably poor design, but it's here for backward compatibility.
+ */
+ while ((result = PQgetResult(conn)) != NULL)
+ {
+ ExecStatusType resultStatus = result->resultStatus;
+
+ PQclear(result); /* only need its status */
+ if (resultStatus == PGRES_COPY_IN)
+ {
+ /* get out of a COPY IN state */
+ if (PQputCopyEnd(conn,
+ libpq_gettext("COPY terminated by new PQexec")) < 0)
+ return false;
+ /* keep waiting to swallow the copy's failure message */
+ }
+ else if (resultStatus == PGRES_COPY_OUT)
+ {
+ /*
+ * Get out of a COPY OUT state: we just switch back to BUSY and
+ * allow the remaining COPY data to be dropped on the floor.
+ */
+ conn->asyncStatus = PGASYNC_BUSY;
+ /* keep waiting to swallow the copy's completion message */
+ }
+ else if (resultStatus == PGRES_COPY_BOTH)
+ {
+ /* We don't allow PQexec during COPY BOTH */
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("PQexec not allowed during COPY BOTH\n"));
+ return false;
+ }
+ /* check for loss of connection, too */
+ if (conn->status == CONNECTION_BAD)
+ return false;
+ }
+
+ /* OK to send a command */
+ return true;
+}
+
+/*
+ * Common code for PQexec and sibling routines: wait for command result
+ */
+static PGresult *
+PQexecFinish(PGconn *conn)
+{
+ PGresult *result;
+ PGresult *lastResult;
+
+ /*
+ * For backwards compatibility, return the last result if there are more
+ * than one. (We used to have logic here to concatenate successive error
+ * messages, but now that happens automatically, since conn->errorMessage
+ * will continue to accumulate errors throughout this loop.)
+ *
+ * We have to stop if we see copy in/out/both, however. We will resume
+ * parsing after application performs the data transfer.
+ *
+ * Also stop if the connection is lost (else we'll loop infinitely).
+ */
+ lastResult = NULL;
+ while ((result = PQgetResult(conn)) != NULL)
+ {
+ if (lastResult)
+ PQclear(lastResult);
+ lastResult = result;
+ if (result->resultStatus == PGRES_COPY_IN ||
+ result->resultStatus == PGRES_COPY_OUT ||
+ result->resultStatus == PGRES_COPY_BOTH ||
+ conn->status == CONNECTION_BAD)
+ break;
+ }
+
+ return lastResult;
+}
+
+/*
+ * PQdescribePrepared
+ * Obtain information about a previously prepared statement
+ *
+ * If the query was not even sent, return NULL; conn->errorMessage is set to
+ * a relevant message.
+ * If the query was sent, a new PGresult is returned (which could indicate
+ * either success or failure). On success, the PGresult contains status
+ * PGRES_COMMAND_OK, and its parameter and column-heading fields describe
+ * the statement's inputs and outputs respectively.
+ * The user is responsible for freeing the PGresult via PQclear()
+ * when done with it.
+ */
+PGresult *
+PQdescribePrepared(PGconn *conn, const char *stmt)
+{
+ if (!PQexecStart(conn))
+ return NULL;
+ if (!PQsendDescribe(conn, 'S', stmt))
+ return NULL;
+ return PQexecFinish(conn);
+}
+
+/*
+ * PQdescribePortal
+ * Obtain information about a previously created portal
+ *
+ * This is much like PQdescribePrepared, except that no parameter info is
+ * returned. Note that at the moment, libpq doesn't really expose portals
+ * to the client; but this can be used with a portal created by a SQL
+ * DECLARE CURSOR command.
+ */
+PGresult *
+PQdescribePortal(PGconn *conn, const char *portal)
+{
+ if (!PQexecStart(conn))
+ return NULL;
+ if (!PQsendDescribe(conn, 'P', portal))
+ return NULL;
+ return PQexecFinish(conn);
+}
+
+/*
+ * PQsendDescribePrepared
+ * Submit a Describe Statement command, but don't wait for it to finish
+ *
+ * Returns: 1 if successfully submitted
+ * 0 if error (conn->errorMessage is set)
+ */
+int
+PQsendDescribePrepared(PGconn *conn, const char *stmt)
+{
+ return PQsendDescribe(conn, 'S', stmt);
+}
+
+/*
+ * PQsendDescribePortal
+ * Submit a Describe Portal command, but don't wait for it to finish
+ *
+ * Returns: 1 if successfully submitted
+ * 0 if error (conn->errorMessage is set)
+ */
+int
+PQsendDescribePortal(PGconn *conn, const char *portal)
+{
+ return PQsendDescribe(conn, 'P', portal);
+}
+
+/*
+ * PQsendDescribe
+ * Common code to send a Describe command
+ *
+ * Available options for desc_type are
+ * 'S' to describe a prepared statement; or
+ * 'P' to describe a portal.
+ * Returns 1 on success and 0 on failure.
+ */
+static int
+PQsendDescribe(PGconn *conn, char desc_type, const char *desc_target)
+{
+ PGcmdQueueEntry *entry = NULL;
+
+ /* Treat null desc_target as empty string */
+ if (!desc_target)
+ desc_target = "";
+
+ if (!PQsendQueryStart(conn, true))
+ return 0;
+
+ entry = pqAllocCmdQueueEntry(conn);
+ if (entry == NULL)
+ return 0; /* error msg already set */
+
+ /* construct the Describe message */
+ if (pqPutMsgStart('D', conn) < 0 ||
+ pqPutc(desc_type, conn) < 0 ||
+ pqPuts(desc_target, conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+
+ /* construct the Sync message */
+ if (conn->pipelineStatus == PQ_PIPELINE_OFF)
+ {
+ if (pqPutMsgStart('S', conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+ }
+
+ /* remember we are doing a Describe */
+ entry->queryclass = PGQUERY_DESCRIBE;
+
+ /*
+ * Give the data a push (in pipeline mode, only if we're past the size
+ * threshold). In nonblock mode, don't complain if we're unable to send
+ * it all; PQgetResult() will do any additional flushing needed.
+ */
+ if (pqPipelineFlush(conn) < 0)
+ goto sendFailed;
+
+ /* OK, it's launched! */
+ pqAppendCmdQueueEntry(conn, entry);
+
+ return 1;
+
+sendFailed:
+ pqRecycleCmdQueueEntry(conn, entry);
+ /* error message should be set up already */
+ return 0;
+}
+
+/*
+ * PQnotifies
+ * returns a PGnotify* structure of the latest async notification
+ * that has not yet been handled
+ *
+ * returns NULL, if there is currently
+ * no unhandled async notification from the backend
+ *
+ * the CALLER is responsible for FREE'ing the structure returned
+ *
+ * Note that this function does not read any new data from the socket;
+ * so usually, caller should call PQconsumeInput() first.
+ */
+PGnotify *
+PQnotifies(PGconn *conn)
+{
+ PGnotify *event;
+
+ if (!conn)
+ return NULL;
+
+ /* Parse any available data to see if we can extract NOTIFY messages. */
+ parseInput(conn);
+
+ event = conn->notifyHead;
+ if (event)
+ {
+ conn->notifyHead = event->next;
+ if (!conn->notifyHead)
+ conn->notifyTail = NULL;
+ event->next = NULL; /* don't let app see the internal state */
+ }
+ return event;
+}
+
+/*
+ * PQputCopyData - send some data to the backend during COPY IN or COPY BOTH
+ *
+ * Returns 1 if successful, 0 if data could not be sent (only possible
+ * in nonblock mode), or -1 if an error occurs.
+ */
+int
+PQputCopyData(PGconn *conn, const char *buffer, int nbytes)
+{
+ if (!conn)
+ return -1;
+ if (conn->asyncStatus != PGASYNC_COPY_IN &&
+ conn->asyncStatus != PGASYNC_COPY_BOTH)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("no COPY in progress\n"));
+ return -1;
+ }
+
+ /*
+ * Process any NOTICE or NOTIFY messages that might be pending in the
+ * input buffer. Since the server might generate many notices during the
+ * COPY, we want to clean those out reasonably promptly to prevent
+ * indefinite expansion of the input buffer. (Note: the actual read of
+ * input data into the input buffer happens down inside pqSendSome, but
+ * it's not authorized to get rid of the data again.)
+ */
+ parseInput(conn);
+
+ if (nbytes > 0)
+ {
+ /*
+ * Try to flush any previously sent data in preference to growing the
+ * output buffer. If we can't enlarge the buffer enough to hold the
+ * data, return 0 in the nonblock case, else hard error. (For
+ * simplicity, always assume 5 bytes of overhead.)
+ */
+ if ((conn->outBufSize - conn->outCount - 5) < nbytes)
+ {
+ if (pqFlush(conn) < 0)
+ return -1;
+ if (pqCheckOutBufferSpace(conn->outCount + 5 + (size_t) nbytes,
+ conn))
+ return pqIsnonblocking(conn) ? 0 : -1;
+ }
+ /* Send the data (too simple to delegate to fe-protocol files) */
+ if (pqPutMsgStart('d', conn) < 0 ||
+ pqPutnchar(buffer, nbytes, conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ return -1;
+ }
+ return 1;
+}
+
+/*
+ * PQputCopyEnd - send EOF indication to the backend during COPY IN
+ *
+ * After calling this, use PQgetResult() to check command completion status.
+ *
+ * Returns 1 if successful, 0 if data could not be sent (only possible
+ * in nonblock mode), or -1 if an error occurs.
+ */
+int
+PQputCopyEnd(PGconn *conn, const char *errormsg)
+{
+ if (!conn)
+ return -1;
+ if (conn->asyncStatus != PGASYNC_COPY_IN &&
+ conn->asyncStatus != PGASYNC_COPY_BOTH)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("no COPY in progress\n"));
+ return -1;
+ }
+
+ /*
+ * Send the COPY END indicator. This is simple enough that we don't
+ * bother delegating it to the fe-protocol files.
+ */
+ if (errormsg)
+ {
+ /* Send COPY FAIL */
+ if (pqPutMsgStart('f', conn) < 0 ||
+ pqPuts(errormsg, conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ return -1;
+ }
+ else
+ {
+ /* Send COPY DONE */
+ if (pqPutMsgStart('c', conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ return -1;
+ }
+
+ /*
+ * If we sent the COPY command in extended-query mode, we must issue a
+ * Sync as well.
+ */
+ if (conn->cmd_queue_head &&
+ conn->cmd_queue_head->queryclass != PGQUERY_SIMPLE)
+ {
+ if (pqPutMsgStart('S', conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ return -1;
+ }
+
+ /* Return to active duty */
+ if (conn->asyncStatus == PGASYNC_COPY_BOTH)
+ conn->asyncStatus = PGASYNC_COPY_OUT;
+ else
+ conn->asyncStatus = PGASYNC_BUSY;
+
+ /* Try to flush data */
+ if (pqFlush(conn) < 0)
+ return -1;
+
+ return 1;
+}
+
+/*
+ * PQgetCopyData - read a row of data from the backend during COPY OUT
+ * or COPY BOTH
+ *
+ * If successful, sets *buffer to point to a malloc'd row of data, and
+ * returns row length (always > 0) as result.
+ * Returns 0 if no row available yet (only possible if async is true),
+ * -1 if end of copy (consult PQgetResult), or -2 if error (consult
+ * PQerrorMessage).
+ */
+int
+PQgetCopyData(PGconn *conn, char **buffer, int async)
+{
+ *buffer = NULL; /* for all failure cases */
+ if (!conn)
+ return -2;
+ if (conn->asyncStatus != PGASYNC_COPY_OUT &&
+ conn->asyncStatus != PGASYNC_COPY_BOTH)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("no COPY in progress\n"));
+ return -2;
+ }
+ return pqGetCopyData3(conn, buffer, async);
+}
+
+/*
+ * PQgetline - gets a newline-terminated string from the backend.
+ *
+ * Chiefly here so that applications can use "COPY <rel> to stdout"
+ * and read the output string. Returns a null-terminated string in s.
+ *
+ * XXX this routine is now deprecated, because it can't handle binary data.
+ * If called during a COPY BINARY we return EOF.
+ *
+ * PQgetline reads up to maxlen-1 characters (like fgets(3)) but strips
+ * the terminating \n (like gets(3)).
+ *
+ * CAUTION: the caller is responsible for detecting the end-of-copy signal
+ * (a line containing just "\.") when using this routine.
+ *
+ * RETURNS:
+ * EOF if error (eg, invalid arguments are given)
+ * 0 if EOL is reached (i.e., \n has been read)
+ * (this is required for backward-compatibility -- this
+ * routine used to always return EOF or 0, assuming that
+ * the line ended within maxlen bytes.)
+ * 1 in other cases (i.e., the buffer was filled before \n is reached)
+ */
+int
+PQgetline(PGconn *conn, char *s, int maxlen)
+{
+ if (!s || maxlen <= 0)
+ return EOF;
+ *s = '\0';
+ /* maxlen must be at least 3 to hold the \. terminator! */
+ if (maxlen < 3)
+ return EOF;
+
+ if (!conn)
+ return EOF;
+
+ return pqGetline3(conn, s, maxlen);
+}
+
+/*
+ * PQgetlineAsync - gets a COPY data row without blocking.
+ *
+ * This routine is for applications that want to do "COPY <rel> to stdout"
+ * asynchronously, that is without blocking. Having issued the COPY command
+ * and gotten a PGRES_COPY_OUT response, the app should call PQconsumeInput
+ * and this routine until the end-of-data signal is detected. Unlike
+ * PQgetline, this routine takes responsibility for detecting end-of-data.
+ *
+ * On each call, PQgetlineAsync will return data if a complete data row
+ * is available in libpq's input buffer. Otherwise, no data is returned
+ * until the rest of the row arrives.
+ *
+ * If -1 is returned, the end-of-data signal has been recognized (and removed
+ * from libpq's input buffer). The caller *must* next call PQendcopy and
+ * then return to normal processing.
+ *
+ * RETURNS:
+ * -1 if the end-of-copy-data marker has been recognized
+ * 0 if no data is available
+ * >0 the number of bytes returned.
+ *
+ * The data returned will not extend beyond a data-row boundary. If possible
+ * a whole row will be returned at one time. But if the buffer offered by
+ * the caller is too small to hold a row sent by the backend, then a partial
+ * data row will be returned. In text mode this can be detected by testing
+ * whether the last returned byte is '\n' or not.
+ *
+ * The returned data is *not* null-terminated.
+ */
+
+int
+PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
+{
+ if (!conn)
+ return -1;
+
+ return pqGetlineAsync3(conn, buffer, bufsize);
+}
+
+/*
+ * PQputline -- sends a string to the backend during COPY IN.
+ * Returns 0 if OK, EOF if not.
+ *
+ * This is deprecated primarily because the return convention doesn't allow
+ * caller to tell the difference between a hard error and a nonblock-mode
+ * send failure.
+ */
+int
+PQputline(PGconn *conn, const char *s)
+{
+ return PQputnbytes(conn, s, strlen(s));
+}
+
+/*
+ * PQputnbytes -- like PQputline, but buffer need not be null-terminated.
+ * Returns 0 if OK, EOF if not.
+ */
+int
+PQputnbytes(PGconn *conn, const char *buffer, int nbytes)
+{
+ if (PQputCopyData(conn, buffer, nbytes) > 0)
+ return 0;
+ else
+ return EOF;
+}
+
+/*
+ * PQendcopy
+ * After completing the data transfer portion of a copy in/out,
+ * the application must call this routine to finish the command protocol.
+ *
+ * This is deprecated; it's cleaner to use PQgetResult to get the transfer
+ * status.
+ *
+ * RETURNS:
+ * 0 on success
+ * 1 on failure
+ */
+int
+PQendcopy(PGconn *conn)
+{
+ if (!conn)
+ return 0;
+
+ return pqEndcopy3(conn);
+}
+
+
+/* ----------------
+ * PQfn - Send a function call to the POSTGRES backend.
+ *
+ * conn : backend connection
+ * fnid : OID of function to be called
+ * result_buf : pointer to result buffer
+ * result_len : actual length of result is returned here
+ * result_is_int : If the result is an integer, this must be 1,
+ * otherwise this should be 0
+ * args : pointer to an array of function arguments
+ * (each has length, if integer, and value/pointer)
+ * nargs : # of arguments in args array.
+ *
+ * RETURNS
+ * PGresult with status = PGRES_COMMAND_OK if successful.
+ * *result_len is > 0 if there is a return value, 0 if not.
+ * PGresult with status = PGRES_FATAL_ERROR if backend returns an error.
+ * NULL on communications failure. conn->errorMessage will be set.
+ * ----------------
+ */
+
+PGresult *
+PQfn(PGconn *conn,
+ int fnid,
+ int *result_buf,
+ int *result_len,
+ int result_is_int,
+ const PQArgBlock *args,
+ int nargs)
+{
+ *result_len = 0;
+
+ if (!conn)
+ return NULL;
+
+ /*
+ * Since this is the beginning of a query cycle, reset the error buffer.
+ */
+ resetPQExpBuffer(&conn->errorMessage);
+
+ if (conn->pipelineStatus != PQ_PIPELINE_OFF)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("PQfn not allowed in pipeline mode\n"));
+ return NULL;
+ }
+
+ if (conn->sock == PGINVALID_SOCKET || conn->asyncStatus != PGASYNC_IDLE ||
+ conn->result != NULL)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("connection in wrong state\n"));
+ return NULL;
+ }
+
+ return pqFunctionCall3(conn, fnid,
+ result_buf, result_len,
+ result_is_int,
+ args, nargs);
+}
+
+/* ====== Pipeline mode support ======== */
+
+/*
+ * PQenterPipelineMode
+ * Put an idle connection in pipeline mode.
+ *
+ * Returns 1 on success. On failure, errorMessage is set and 0 is returned.
+ *
+ * Commands submitted after this can be pipelined on the connection;
+ * there's no requirement to wait for one to finish before the next is
+ * dispatched.
+ *
+ * Queuing of a new query or syncing during COPY is not allowed.
+ *
+ * A set of commands is terminated by a PQpipelineSync. Multiple sync
+ * points can be established while in pipeline mode. Pipeline mode can
+ * be exited by calling PQexitPipelineMode() once all results are processed.
+ *
+ * This doesn't actually send anything on the wire, it just puts libpq
+ * into a state where it can pipeline work.
+ */
+int
+PQenterPipelineMode(PGconn *conn)
+{
+ if (!conn)
+ return 0;
+
+ /* succeed with no action if already in pipeline mode */
+ if (conn->pipelineStatus != PQ_PIPELINE_OFF)
+ return 1;
+
+ if (conn->asyncStatus != PGASYNC_IDLE)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("cannot enter pipeline mode, connection not idle\n"));
+ return 0;
+ }
+
+ conn->pipelineStatus = PQ_PIPELINE_ON;
+
+ return 1;
+}
+
+/*
+ * PQexitPipelineMode
+ * End pipeline mode and return to normal command mode.
+ *
+ * Returns 1 in success (pipeline mode successfully ended, or not in pipeline
+ * mode).
+ *
+ * Returns 0 if in pipeline mode and cannot be ended yet. Error message will
+ * be set.
+ */
+int
+PQexitPipelineMode(PGconn *conn)
+{
+ if (!conn)
+ return 0;
+
+ if (conn->pipelineStatus == PQ_PIPELINE_OFF &&
+ (conn->asyncStatus == PGASYNC_IDLE ||
+ conn->asyncStatus == PGASYNC_PIPELINE_IDLE) &&
+ conn->cmd_queue_head == NULL)
+ return 1;
+
+ switch (conn->asyncStatus)
+ {
+ case PGASYNC_READY:
+ case PGASYNC_READY_MORE:
+ /* there are some uncollected results */
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("cannot exit pipeline mode with uncollected results\n"));
+ return 0;
+
+ case PGASYNC_BUSY:
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("cannot exit pipeline mode while busy\n"));
+ return 0;
+
+ case PGASYNC_IDLE:
+ case PGASYNC_PIPELINE_IDLE:
+ /* OK */
+ break;
+
+ case PGASYNC_COPY_IN:
+ case PGASYNC_COPY_OUT:
+ case PGASYNC_COPY_BOTH:
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("cannot exit pipeline mode while in COPY\n"));
+ }
+
+ /* still work to process */
+ if (conn->cmd_queue_head != NULL)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("cannot exit pipeline mode with uncollected results\n"));
+ return 0;
+ }
+
+ conn->pipelineStatus = PQ_PIPELINE_OFF;
+ conn->asyncStatus = PGASYNC_IDLE;
+
+ /* Flush any pending data in out buffer */
+ if (pqFlush(conn) < 0)
+ return 0; /* error message is setup already */
+ return 1;
+}
+
+/*
+ * pqCommandQueueAdvance
+ * Remove one query from the command queue, when we receive
+ * all results from the server that pertain to it.
+ */
+void
+pqCommandQueueAdvance(PGconn *conn)
+{
+ PGcmdQueueEntry *prevquery;
+
+ if (conn->cmd_queue_head == NULL)
+ return;
+
+ /* delink from queue */
+ prevquery = conn->cmd_queue_head;
+ conn->cmd_queue_head = conn->cmd_queue_head->next;
+
+ /* If the queue is now empty, reset the tail too */
+ if (conn->cmd_queue_head == NULL)
+ conn->cmd_queue_tail = NULL;
+
+ /* and make it recyclable */
+ prevquery->next = NULL;
+ pqRecycleCmdQueueEntry(conn, prevquery);
+}
+
+/*
+ * pqPipelineProcessQueue: subroutine for PQgetResult
+ * In pipeline mode, start processing the results of the next query in the queue.
+ */
+static void
+pqPipelineProcessQueue(PGconn *conn)
+{
+ switch (conn->asyncStatus)
+ {
+ case PGASYNC_COPY_IN:
+ case PGASYNC_COPY_OUT:
+ case PGASYNC_COPY_BOTH:
+ case PGASYNC_READY:
+ case PGASYNC_READY_MORE:
+ case PGASYNC_BUSY:
+ /* client still has to process current query or results */
+ return;
+
+ case PGASYNC_IDLE:
+ /*
+ * If we're in IDLE mode and there's some command in the queue,
+ * get us into PIPELINE_IDLE mode and process normally. Otherwise
+ * there's nothing for us to do.
+ */
+ if (conn->cmd_queue_head != NULL)
+ {
+ conn->asyncStatus = PGASYNC_PIPELINE_IDLE;
+ break;
+ }
+ return;
+
+ case PGASYNC_PIPELINE_IDLE:
+ Assert(conn->pipelineStatus != PQ_PIPELINE_OFF);
+ /* next query please */
+ break;
+ }
+
+ /*
+ * If there are no further commands to process in the queue, get us in
+ * "real idle" mode now.
+ */
+ if (conn->cmd_queue_head == NULL)
+ {
+ conn->asyncStatus = PGASYNC_IDLE;
+ return;
+ }
+
+ /* Initialize async result-accumulation state */
+ pqClearAsyncResult(conn);
+
+ /*
+ * Reset single-row processing mode. (Client has to set it up for each
+ * query, if desired.)
+ */
+ conn->singleRowMode = false;
+
+ if (conn->pipelineStatus == PQ_PIPELINE_ABORTED &&
+ conn->cmd_queue_head->queryclass != PGQUERY_SYNC)
+ {
+ /*
+ * In an aborted pipeline we don't get anything from the server for
+ * each result; we're just discarding commands from the queue until we
+ * get to the next sync from the server.
+ *
+ * The PGRES_PIPELINE_ABORTED results tell the client that its queries
+ * got aborted.
+ */
+ conn->result = PQmakeEmptyPGresult(conn, PGRES_PIPELINE_ABORTED);
+ if (!conn->result)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("out of memory\n"));
+ pqSaveErrorResult(conn);
+ return;
+ }
+ conn->asyncStatus = PGASYNC_READY;
+ }
+ else
+ {
+ /* allow parsing to continue */
+ conn->asyncStatus = PGASYNC_BUSY;
+ }
+}
+
+/*
+ * PQpipelineSync
+ * Send a Sync message as part of a pipeline, and flush to server
+ *
+ * It's legal to start submitting more commands in the pipeline immediately,
+ * without waiting for the results of the current pipeline. There's no need to
+ * end pipeline mode and start it again.
+ *
+ * If a command in a pipeline fails, every subsequent command up to and including
+ * the result to the Sync message sent by PQpipelineSync gets set to
+ * PGRES_PIPELINE_ABORTED state. If the whole pipeline is processed without
+ * error, a PGresult with PGRES_PIPELINE_SYNC is produced.
+ *
+ * Queries can already have been sent before PQpipelineSync is called, but
+ * PQpipelineSync need to be called before retrieving command results.
+ *
+ * The connection will remain in pipeline mode and unavailable for new
+ * synchronous command execution functions until all results from the pipeline
+ * are processed by the client.
+ */
+int
+PQpipelineSync(PGconn *conn)
+{
+ PGcmdQueueEntry *entry;
+
+ if (!conn)
+ return 0;
+
+ if (conn->pipelineStatus == PQ_PIPELINE_OFF)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("cannot send pipeline when not in pipeline mode\n"));
+ return 0;
+ }
+
+ switch (conn->asyncStatus)
+ {
+ case PGASYNC_COPY_IN:
+ case PGASYNC_COPY_OUT:
+ case PGASYNC_COPY_BOTH:
+ /* should be unreachable */
+ appendPQExpBufferStr(&conn->errorMessage,
+ "internal error: cannot send pipeline while in COPY\n");
+ return 0;
+ case PGASYNC_READY:
+ case PGASYNC_READY_MORE:
+ case PGASYNC_BUSY:
+ case PGASYNC_IDLE:
+ case PGASYNC_PIPELINE_IDLE:
+ /* OK to send sync */
+ break;
+ }
+
+ entry = pqAllocCmdQueueEntry(conn);
+ if (entry == NULL)
+ return 0; /* error msg already set */
+
+ entry->queryclass = PGQUERY_SYNC;
+ entry->query = NULL;
+
+ /* construct the Sync message */
+ if (pqPutMsgStart('S', conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ goto sendFailed;
+
+ /*
+ * Give the data a push. In nonblock mode, don't complain if we're unable
+ * to send it all; PQgetResult() will do any additional flushing needed.
+ */
+ if (PQflush(conn) < 0)
+ goto sendFailed;
+
+ /* OK, it's launched! */
+ pqAppendCmdQueueEntry(conn, entry);
+
+ return 1;
+
+sendFailed:
+ pqRecycleCmdQueueEntry(conn, entry);
+ /* error message should be set up already */
+ return 0;
+}
+
+/*
+ * PQsendFlushRequest
+ * Send request for server to flush its buffer. Useful in pipeline
+ * mode when a sync point is not desired.
+ */
+int
+PQsendFlushRequest(PGconn *conn)
+{
+ if (!conn)
+ return 0;
+
+ /* Don't try to send if we know there's no live connection. */
+ if (conn->status != CONNECTION_OK)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("no connection to the server\n"));
+ return 0;
+ }
+
+ /* Can't send while already busy, either, unless enqueuing for later */
+ if (conn->asyncStatus != PGASYNC_IDLE &&
+ conn->pipelineStatus == PQ_PIPELINE_OFF)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("another command is already in progress\n"));
+ return 0;
+ }
+
+ if (pqPutMsgStart('H', conn) < 0 ||
+ pqPutMsgEnd(conn) < 0)
+ {
+ return 0;
+ }
+
+ return 1;
+}
+
+/* ====== accessor funcs for PGresult ======== */
+
+ExecStatusType
+PQresultStatus(const PGresult *res)
+{
+ if (!res)
+ return PGRES_FATAL_ERROR;
+ return res->resultStatus;
+}
+
+char *
+PQresStatus(ExecStatusType status)
+{
+ if ((unsigned int) status >= lengthof(pgresStatus))
+ return libpq_gettext("invalid ExecStatusType code");
+ return pgresStatus[status];
+}
+
+char *
+PQresultErrorMessage(const PGresult *res)
+{
+ if (!res || !res->errMsg)
+ return "";
+ return res->errMsg;
+}
+
+char *
+PQresultVerboseErrorMessage(const PGresult *res,
+ PGVerbosity verbosity,
+ PGContextVisibility show_context)
+{
+ PQExpBufferData workBuf;
+
+ /*
+ * Because the caller is expected to free the result string, we must
+ * strdup any constant result. We use plain strdup and document that
+ * callers should expect NULL if out-of-memory.
+ */
+ if (!res ||
+ (res->resultStatus != PGRES_FATAL_ERROR &&
+ res->resultStatus != PGRES_NONFATAL_ERROR))
+ return strdup(libpq_gettext("PGresult is not an error result\n"));
+
+ initPQExpBuffer(&workBuf);
+
+ pqBuildErrorMessage3(&workBuf, res, verbosity, show_context);
+
+ /* If insufficient memory to format the message, fail cleanly */
+ if (PQExpBufferDataBroken(workBuf))
+ {
+ termPQExpBuffer(&workBuf);
+ return strdup(libpq_gettext("out of memory\n"));
+ }
+
+ return workBuf.data;
+}
+
+char *
+PQresultErrorField(const PGresult *res, int fieldcode)
+{
+ PGMessageField *pfield;
+
+ if (!res)
+ return NULL;
+ for (pfield = res->errFields; pfield != NULL; pfield = pfield->next)
+ {
+ if (pfield->code == fieldcode)
+ return pfield->contents;
+ }
+ return NULL;
+}
+
+int
+PQntuples(const PGresult *res)
+{
+ if (!res)
+ return 0;
+ return res->ntups;
+}
+
+int
+PQnfields(const PGresult *res)
+{
+ if (!res)
+ return 0;
+ return res->numAttributes;
+}
+
+int
+PQbinaryTuples(const PGresult *res)
+{
+ if (!res)
+ return 0;
+ return res->binary;
+}
+
+/*
+ * Helper routines to range-check field numbers and tuple numbers.
+ * Return true if OK, false if not
+ */
+
+static int
+check_field_number(const PGresult *res, int field_num)
+{
+ if (!res)
+ return false; /* no way to display error message... */
+ if (field_num < 0 || field_num >= res->numAttributes)
+ {
+ pqInternalNotice(&res->noticeHooks,
+ "column number %d is out of range 0..%d",
+ field_num, res->numAttributes - 1);
+ return false;
+ }
+ return true;
+}
+
+static int
+check_tuple_field_number(const PGresult *res,
+ int tup_num, int field_num)
+{
+ if (!res)
+ return false; /* no way to display error message... */
+ if (tup_num < 0 || tup_num >= res->ntups)
+ {
+ pqInternalNotice(&res->noticeHooks,
+ "row number %d is out of range 0..%d",
+ tup_num, res->ntups - 1);
+ return false;
+ }
+ if (field_num < 0 || field_num >= res->numAttributes)
+ {
+ pqInternalNotice(&res->noticeHooks,
+ "column number %d is out of range 0..%d",
+ field_num, res->numAttributes - 1);
+ return false;
+ }
+ return true;
+}
+
+static int
+check_param_number(const PGresult *res, int param_num)
+{
+ if (!res)
+ return false; /* no way to display error message... */
+ if (param_num < 0 || param_num >= res->numParameters)
+ {
+ pqInternalNotice(&res->noticeHooks,
+ "parameter number %d is out of range 0..%d",
+ param_num, res->numParameters - 1);
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * returns NULL if the field_num is invalid
+ */
+char *
+PQfname(const PGresult *res, int field_num)
+{
+ if (!check_field_number(res, field_num))
+ return NULL;
+ if (res->attDescs)
+ return res->attDescs[field_num].name;
+ else
+ return NULL;
+}
+
+/*
+ * PQfnumber: find column number given column name
+ *
+ * The column name is parsed as if it were in a SQL statement, including
+ * case-folding and double-quote processing. But note a possible gotcha:
+ * downcasing in the frontend might follow different locale rules than
+ * downcasing in the backend...
+ *
+ * Returns -1 if no match. In the present backend it is also possible
+ * to have multiple matches, in which case the first one is found.
+ */
+int
+PQfnumber(const PGresult *res, const char *field_name)
+{
+ char *field_case;
+ bool in_quotes;
+ bool all_lower = true;
+ const char *iptr;
+ char *optr;
+ int i;
+
+ if (!res)
+ return -1;
+
+ /*
+ * Note: it is correct to reject a zero-length input string; the proper
+ * input to match a zero-length field name would be "".
+ */
+ if (field_name == NULL ||
+ field_name[0] == '\0' ||
+ res->attDescs == NULL)
+ return -1;
+
+ /*
+ * Check if we can avoid the strdup() and related work because the
+ * passed-in string wouldn't be changed before we do the check anyway.
+ */
+ for (iptr = field_name; *iptr; iptr++)
+ {
+ char c = *iptr;
+
+ if (c == '"' || c != pg_tolower((unsigned char) c))
+ {
+ all_lower = false;
+ break;
+ }
+ }
+
+ if (all_lower)
+ for (i = 0; i < res->numAttributes; i++)
+ if (strcmp(field_name, res->attDescs[i].name) == 0)
+ return i;
+
+ /* Fall through to the normal check if that didn't work out. */
+
+ /*
+ * Note: this code will not reject partially quoted strings, eg
+ * foo"BAR"foo will become fooBARfoo when it probably ought to be an error
+ * condition.
+ */
+ field_case = strdup(field_name);
+ if (field_case == NULL)
+ return -1; /* grotty */
+
+ in_quotes = false;
+ optr = field_case;
+ for (iptr = field_case; *iptr; iptr++)
+ {
+ char c = *iptr;
+
+ if (in_quotes)
+ {
+ if (c == '"')
+ {
+ if (iptr[1] == '"')
+ {
+ /* doubled quotes become a single quote */
+ *optr++ = '"';
+ iptr++;
+ }
+ else
+ in_quotes = false;
+ }
+ else
+ *optr++ = c;
+ }
+ else if (c == '"')
+ in_quotes = true;
+ else
+ {
+ c = pg_tolower((unsigned char) c);
+ *optr++ = c;
+ }
+ }
+ *optr = '\0';
+
+ for (i = 0; i < res->numAttributes; i++)
+ {
+ if (strcmp(field_case, res->attDescs[i].name) == 0)
+ {
+ free(field_case);
+ return i;
+ }
+ }
+ free(field_case);
+ return -1;
+}
+
+Oid
+PQftable(const PGresult *res, int field_num)
+{
+ if (!check_field_number(res, field_num))
+ return InvalidOid;
+ if (res->attDescs)
+ return res->attDescs[field_num].tableid;
+ else
+ return InvalidOid;
+}
+
+int
+PQftablecol(const PGresult *res, int field_num)
+{
+ if (!check_field_number(res, field_num))
+ return 0;
+ if (res->attDescs)
+ return res->attDescs[field_num].columnid;
+ else
+ return 0;
+}
+
+int
+PQfformat(const PGresult *res, int field_num)
+{
+ if (!check_field_number(res, field_num))
+ return 0;
+ if (res->attDescs)
+ return res->attDescs[field_num].format;
+ else
+ return 0;
+}
+
+Oid
+PQftype(const PGresult *res, int field_num)
+{
+ if (!check_field_number(res, field_num))
+ return InvalidOid;
+ if (res->attDescs)
+ return res->attDescs[field_num].typid;
+ else
+ return InvalidOid;
+}
+
+int
+PQfsize(const PGresult *res, int field_num)
+{
+ if (!check_field_number(res, field_num))
+ return 0;
+ if (res->attDescs)
+ return res->attDescs[field_num].typlen;
+ else
+ return 0;
+}
+
+int
+PQfmod(const PGresult *res, int field_num)
+{
+ if (!check_field_number(res, field_num))
+ return 0;
+ if (res->attDescs)
+ return res->attDescs[field_num].atttypmod;
+ else
+ return 0;
+}
+
+char *
+PQcmdStatus(PGresult *res)
+{
+ if (!res)
+ return NULL;
+ return res->cmdStatus;
+}
+
+/*
+ * PQoidStatus -
+ * if the last command was an INSERT, return the oid string
+ * if not, return ""
+ */
+char *
+PQoidStatus(const PGresult *res)
+{
+ /*
+ * This must be enough to hold the result. Don't laugh, this is better
+ * than what this function used to do.
+ */
+ static char buf[24];
+
+ size_t len;
+
+ if (!res || strncmp(res->cmdStatus, "INSERT ", 7) != 0)
+ return "";
+
+ len = strspn(res->cmdStatus + 7, "0123456789");
+ if (len > sizeof(buf) - 1)
+ len = sizeof(buf) - 1;
+ memcpy(buf, res->cmdStatus + 7, len);
+ buf[len] = '\0';
+
+ return buf;
+}
+
+/*
+ * PQoidValue -
+ * a perhaps preferable form of the above which just returns
+ * an Oid type
+ */
+Oid
+PQoidValue(const PGresult *res)
+{
+ char *endptr = NULL;
+ unsigned long result;
+
+ if (!res ||
+ strncmp(res->cmdStatus, "INSERT ", 7) != 0 ||
+ res->cmdStatus[7] < '0' ||
+ res->cmdStatus[7] > '9')
+ return InvalidOid;
+
+ result = strtoul(res->cmdStatus + 7, &endptr, 10);
+
+ if (!endptr || (*endptr != ' ' && *endptr != '\0'))
+ return InvalidOid;
+ else
+ return (Oid) result;
+}
+
+
+/*
+ * PQcmdTuples -
+ * If the last command was INSERT/UPDATE/DELETE/MOVE/FETCH/COPY, return
+ * a string containing the number of inserted/affected tuples. If not,
+ * return "".
+ *
+ * XXX: this should probably return an int
+ */
+char *
+PQcmdTuples(PGresult *res)
+{
+ char *p,
+ *c;
+
+ if (!res)
+ return "";
+
+ if (strncmp(res->cmdStatus, "INSERT ", 7) == 0)
+ {
+ p = res->cmdStatus + 7;
+ /* INSERT: skip oid and space */
+ while (*p && *p != ' ')
+ p++;
+ if (*p == 0)
+ goto interpret_error; /* no space? */
+ p++;
+ }
+ else if (strncmp(res->cmdStatus, "SELECT ", 7) == 0 ||
+ strncmp(res->cmdStatus, "DELETE ", 7) == 0 ||
+ strncmp(res->cmdStatus, "UPDATE ", 7) == 0)
+ p = res->cmdStatus + 7;
+ else if (strncmp(res->cmdStatus, "FETCH ", 6) == 0)
+ p = res->cmdStatus + 6;
+ else if (strncmp(res->cmdStatus, "MOVE ", 5) == 0 ||
+ strncmp(res->cmdStatus, "COPY ", 5) == 0)
+ p = res->cmdStatus + 5;
+ else
+ return "";
+
+ /* check that we have an integer (at least one digit, nothing else) */
+ for (c = p; *c; c++)
+ {
+ if (!isdigit((unsigned char) *c))
+ goto interpret_error;
+ }
+ if (c == p)
+ goto interpret_error;
+
+ return p;
+
+interpret_error:
+ pqInternalNotice(&res->noticeHooks,
+ "could not interpret result from server: %s",
+ res->cmdStatus);
+ return "";
+}
+
+/*
+ * PQgetvalue:
+ * return the value of field 'field_num' of row 'tup_num'
+ */
+char *
+PQgetvalue(const PGresult *res, int tup_num, int field_num)
+{
+ if (!check_tuple_field_number(res, tup_num, field_num))
+ return NULL;
+ return res->tuples[tup_num][field_num].value;
+}
+
+/* PQgetlength:
+ * returns the actual length of a field value in bytes.
+ */
+int
+PQgetlength(const PGresult *res, int tup_num, int field_num)
+{
+ if (!check_tuple_field_number(res, tup_num, field_num))
+ return 0;
+ if (res->tuples[tup_num][field_num].len != NULL_LEN)
+ return res->tuples[tup_num][field_num].len;
+ else
+ return 0;
+}
+
+/* PQgetisnull:
+ * returns the null status of a field value.
+ */
+int
+PQgetisnull(const PGresult *res, int tup_num, int field_num)
+{
+ if (!check_tuple_field_number(res, tup_num, field_num))
+ return 1; /* pretend it is null */
+ if (res->tuples[tup_num][field_num].len == NULL_LEN)
+ return 1;
+ else
+ return 0;
+}
+
+/* PQnparams:
+ * returns the number of input parameters of a prepared statement.
+ */
+int
+PQnparams(const PGresult *res)
+{
+ if (!res)
+ return 0;
+ return res->numParameters;
+}
+
+/* PQparamtype:
+ * returns type Oid of the specified statement parameter.
+ */
+Oid
+PQparamtype(const PGresult *res, int param_num)
+{
+ if (!check_param_number(res, param_num))
+ return InvalidOid;
+ if (res->paramDescs)
+ return res->paramDescs[param_num].typid;
+ else
+ return InvalidOid;
+}
+
+
+/* PQsetnonblocking:
+ * sets the PGconn's database connection non-blocking if the arg is true
+ * or makes it blocking if the arg is false, this will not protect
+ * you from PQexec(), you'll only be safe when using the non-blocking API.
+ * Needs to be called only on a connected database connection.
+ */
+int
+PQsetnonblocking(PGconn *conn, int arg)
+{
+ bool barg;
+
+ if (!conn || conn->status == CONNECTION_BAD)
+ return -1;
+
+ barg = (arg ? true : false);
+
+ /* early out if the socket is already in the state requested */
+ if (barg == conn->nonblocking)
+ return 0;
+
+ /*
+ * to guarantee constancy for flushing/query/result-polling behavior we
+ * need to flush the send queue at this point in order to guarantee proper
+ * behavior. this is ok because either they are making a transition _from_
+ * or _to_ blocking mode, either way we can block them.
+ *
+ * Clear errorMessage in case pqFlush adds to it.
+ */
+ resetPQExpBuffer(&conn->errorMessage);
+
+ /* if we are going from blocking to non-blocking flush here */
+ if (pqFlush(conn))
+ return -1;
+
+ conn->nonblocking = barg;
+
+ return 0;
+}
+
+/*
+ * return the blocking status of the database connection
+ * true == nonblocking, false == blocking
+ */
+int
+PQisnonblocking(const PGconn *conn)
+{
+ return pqIsnonblocking(conn);
+}
+
+/* libpq is thread-safe? */
+int
+PQisthreadsafe(void)
+{
+#ifdef ENABLE_THREAD_SAFETY
+ return true;
+#else
+ return false;
+#endif
+}
+
+
+/* try to force data out, really only useful for non-blocking users */
+int
+PQflush(PGconn *conn)
+{
+ return pqFlush(conn);
+}
+
+/*
+ * pqPipelineFlush
+ *
+ * In pipeline mode, data will be flushed only when the out buffer reaches the
+ * threshold value. In non-pipeline mode, it behaves as stock pqFlush.
+ *
+ * Returns 0 on success.
+ */
+static int
+pqPipelineFlush(PGconn *conn)
+{
+ if ((conn->pipelineStatus != PQ_PIPELINE_ON) ||
+ (conn->outCount >= OUTBUFFER_THRESHOLD))
+ return pqFlush(conn);
+ return 0;
+}
+
+
+/*
+ * PQfreemem - safely frees memory allocated
+ *
+ * Needed mostly by Win32, unless multithreaded DLL (/MD in VC6)
+ * Used for freeing memory from PQescapeBytea()/PQunescapeBytea()
+ */
+void
+PQfreemem(void *ptr)
+{
+ free(ptr);
+}
+
+/*
+ * PQfreeNotify - free's the memory associated with a PGnotify
+ *
+ * This function is here only for binary backward compatibility.
+ * New code should use PQfreemem(). A macro will automatically map
+ * calls to PQfreemem. It should be removed in the future. bjm 2003-03-24
+ */
+
+#undef PQfreeNotify
+void PQfreeNotify(PGnotify *notify);
+
+void
+PQfreeNotify(PGnotify *notify)
+{
+ PQfreemem(notify);
+}
+
+
+/*
+ * Escaping arbitrary strings to get valid SQL literal strings.
+ *
+ * Replaces "'" with "''", and if not std_strings, replaces "\" with "\\".
+ *
+ * length is the length of the source string. (Note: if a terminating NUL
+ * is encountered sooner, PQescapeString stops short of "length"; the behavior
+ * is thus rather like strncpy.)
+ *
+ * For safety the buffer at "to" must be at least 2*length + 1 bytes long.
+ * A terminating NUL character is added to the output string, whether the
+ * input is NUL-terminated or not.
+ *
+ * Returns the actual length of the output (not counting the terminating NUL).
+ */
+static size_t
+PQescapeStringInternal(PGconn *conn,
+ char *to, const char *from, size_t length,
+ int *error,
+ int encoding, bool std_strings)
+{
+ const char *source = from;
+ char *target = to;
+ size_t remaining = length;
+
+ if (error)
+ *error = 0;
+
+ while (remaining > 0 && *source != '\0')
+ {
+ char c = *source;
+ int len;
+ int i;
+
+ /* Fast path for plain ASCII */
+ if (!IS_HIGHBIT_SET(c))
+ {
+ /* Apply quoting if needed */
+ if (SQL_STR_DOUBLE(c, !std_strings))
+ *target++ = c;
+ /* Copy the character */
+ *target++ = c;
+ source++;
+ remaining--;
+ continue;
+ }
+
+ /* Slow path for possible multibyte characters */
+ len = pg_encoding_mblen(encoding, source);
+
+ /* Copy the character */
+ for (i = 0; i < len; i++)
+ {
+ if (remaining == 0 || *source == '\0')
+ break;
+ *target++ = *source++;
+ remaining--;
+ }
+
+ /*
+ * If we hit premature end of string (ie, incomplete multibyte
+ * character), try to pad out to the correct length with spaces. We
+ * may not be able to pad completely, but we will always be able to
+ * insert at least one pad space (since we'd not have quoted a
+ * multibyte character). This should be enough to make a string that
+ * the server will error out on.
+ */
+ if (i < len)
+ {
+ if (error)
+ *error = 1;
+ if (conn)
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("incomplete multibyte character\n"));
+ for (; i < len; i++)
+ {
+ if (((size_t) (target - to)) / 2 >= length)
+ break;
+ *target++ = ' ';
+ }
+ break;
+ }
+ }
+
+ /* Write the terminating NUL character. */
+ *target = '\0';
+
+ return target - to;
+}
+
+size_t
+PQescapeStringConn(PGconn *conn,
+ char *to, const char *from, size_t length,
+ int *error)
+{
+ if (!conn)
+ {
+ /* force empty-string result */
+ *to = '\0';
+ if (error)
+ *error = 1;
+ return 0;
+ }
+
+ resetPQExpBuffer(&conn->errorMessage);
+
+ return PQescapeStringInternal(conn, to, from, length, error,
+ conn->client_encoding,
+ conn->std_strings);
+}
+
+size_t
+PQescapeString(char *to, const char *from, size_t length)
+{
+ return PQescapeStringInternal(NULL, to, from, length, NULL,
+ static_client_encoding,
+ static_std_strings);
+}
+
+
+/*
+ * Escape arbitrary strings. If as_ident is true, we escape the result
+ * as an identifier; if false, as a literal. The result is returned in
+ * a newly allocated buffer. If we fail due to an encoding violation or out
+ * of memory condition, we return NULL, storing an error message into conn.
+ */
+static char *
+PQescapeInternal(PGconn *conn, const char *str, size_t len, bool as_ident)
+{
+ const char *s;
+ char *result;
+ char *rp;
+ int num_quotes = 0; /* single or double, depending on as_ident */
+ int num_backslashes = 0;
+ int input_len;
+ int result_size;
+ char quote_char = as_ident ? '"' : '\'';
+
+ /* We must have a connection, else fail immediately. */
+ if (!conn)
+ return NULL;
+
+ resetPQExpBuffer(&conn->errorMessage);
+
+ /* Scan the string for characters that must be escaped. */
+ for (s = str; (s - str) < len && *s != '\0'; ++s)
+ {
+ if (*s == quote_char)
+ ++num_quotes;
+ else if (*s == '\\')
+ ++num_backslashes;
+ else if (IS_HIGHBIT_SET(*s))
+ {
+ int charlen;
+
+ /* Slow path for possible multibyte characters */
+ charlen = pg_encoding_mblen(conn->client_encoding, s);
+
+ /* Multibyte character overruns allowable length. */
+ if ((s - str) + charlen > len || memchr(s, 0, charlen) != NULL)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("incomplete multibyte character\n"));
+ return NULL;
+ }
+
+ /* Adjust s, bearing in mind that for loop will increment it. */
+ s += charlen - 1;
+ }
+ }
+
+ /* Allocate output buffer. */
+ input_len = s - str;
+ result_size = input_len + num_quotes + 3; /* two quotes, plus a NUL */
+ if (!as_ident && num_backslashes > 0)
+ result_size += num_backslashes + 2;
+ result = rp = (char *) malloc(result_size);
+ if (rp == NULL)
+ {
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("out of memory\n"));
+ return NULL;
+ }
+
+ /*
+ * If we are escaping a literal that contains backslashes, we use the
+ * escape string syntax so that the result is correct under either value
+ * of standard_conforming_strings. We also emit a leading space in this
+ * case, to guard against the possibility that the result might be
+ * interpolated immediately following an identifier.
+ */
+ if (!as_ident && num_backslashes > 0)
+ {
+ *rp++ = ' ';
+ *rp++ = 'E';
+ }
+
+ /* Opening quote. */
+ *rp++ = quote_char;
+
+ /*
+ * Use fast path if possible.
+ *
+ * We've already verified that the input string is well-formed in the
+ * current encoding. If it contains no quotes and, in the case of
+ * literal-escaping, no backslashes, then we can just copy it directly to
+ * the output buffer, adding the necessary quotes.
+ *
+ * If not, we must rescan the input and process each character
+ * individually.
+ */
+ if (num_quotes == 0 && (num_backslashes == 0 || as_ident))
+ {
+ memcpy(rp, str, input_len);
+ rp += input_len;
+ }
+ else
+ {
+ for (s = str; s - str < input_len; ++s)
+ {
+ if (*s == quote_char || (!as_ident && *s == '\\'))
+ {
+ *rp++ = *s;
+ *rp++ = *s;
+ }
+ else if (!IS_HIGHBIT_SET(*s))
+ *rp++ = *s;
+ else
+ {
+ int i = pg_encoding_mblen(conn->client_encoding, s);
+
+ while (1)
+ {
+ *rp++ = *s;
+ if (--i == 0)
+ break;
+ ++s; /* for loop will provide the final increment */
+ }
+ }
+ }
+ }
+
+ /* Closing quote and terminating NUL. */
+ *rp++ = quote_char;
+ *rp = '\0';
+
+ return result;
+}
+
+char *
+PQescapeLiteral(PGconn *conn, const char *str, size_t len)
+{
+ return PQescapeInternal(conn, str, len, false);
+}
+
+char *
+PQescapeIdentifier(PGconn *conn, const char *str, size_t len)
+{
+ return PQescapeInternal(conn, str, len, true);
+}
+
+/* HEX encoding support for bytea */
+static const char hextbl[] = "0123456789abcdef";
+
+static const int8 hexlookup[128] = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
+ -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+};
+
+static inline char
+get_hex(char c)
+{
+ int res = -1;
+
+ if (c > 0 && c < 127)
+ res = hexlookup[(unsigned char) c];
+
+ return (char) res;
+}
+
+
+/*
+ * PQescapeBytea - converts from binary string to the
+ * minimal encoding necessary to include the string in an SQL
+ * INSERT statement with a bytea type column as the target.
+ *
+ * We can use either hex or escape (traditional) encoding.
+ * In escape mode, the following transformations are applied:
+ * '\0' == ASCII 0 == \000
+ * '\'' == ASCII 39 == ''
+ * '\\' == ASCII 92 == \\
+ * anything < 0x20, or > 0x7e ---> \ooo
+ * (where ooo is an octal expression)
+ *
+ * If not std_strings, all backslashes sent to the output are doubled.
+ */
+static unsigned char *
+PQescapeByteaInternal(PGconn *conn,
+ const unsigned char *from, size_t from_length,
+ size_t *to_length, bool std_strings, bool use_hex)
+{
+ const unsigned char *vp;
+ unsigned char *rp;
+ unsigned char *result;
+ size_t i;
+ size_t len;
+ size_t bslash_len = (std_strings ? 1 : 2);
+
+ /*
+ * empty string has 1 char ('\0')
+ */
+ len = 1;
+
+ if (use_hex)
+ {
+ len += bslash_len + 1 + 2 * from_length;
+ }
+ else
+ {
+ vp = from;
+ for (i = from_length; i > 0; i--, vp++)
+ {
+ if (*vp < 0x20 || *vp > 0x7e)
+ len += bslash_len + 3;
+ else if (*vp == '\'')
+ len += 2;
+ else if (*vp == '\\')
+ len += bslash_len + bslash_len;
+ else
+ len++;
+ }
+ }
+
+ *to_length = len;
+ rp = result = (unsigned char *) malloc(len);
+ if (rp == NULL)
+ {
+ if (conn)
+ appendPQExpBufferStr(&conn->errorMessage,
+ libpq_gettext("out of memory\n"));
+ return NULL;
+ }
+
+ if (use_hex)
+ {
+ if (!std_strings)
+ *rp++ = '\\';
+ *rp++ = '\\';
+ *rp++ = 'x';
+ }
+
+ vp = from;
+ for (i = from_length; i > 0; i--, vp++)
+ {
+ unsigned char c = *vp;
+
+ if (use_hex)
+ {
+ *rp++ = hextbl[(c >> 4) & 0xF];
+ *rp++ = hextbl[c & 0xF];
+ }
+ else if (c < 0x20 || c > 0x7e)
+ {
+ if (!std_strings)
+ *rp++ = '\\';
+ *rp++ = '\\';
+ *rp++ = (c >> 6) + '0';
+ *rp++ = ((c >> 3) & 07) + '0';
+ *rp++ = (c & 07) + '0';
+ }
+ else if (c == '\'')
+ {
+ *rp++ = '\'';
+ *rp++ = '\'';
+ }
+ else if (c == '\\')
+ {
+ if (!std_strings)
+ {
+ *rp++ = '\\';
+ *rp++ = '\\';
+ }
+ *rp++ = '\\';
+ *rp++ = '\\';
+ }
+ else
+ *rp++ = c;
+ }
+ *rp = '\0';
+
+ return result;
+}
+
+unsigned char *
+PQescapeByteaConn(PGconn *conn,
+ const unsigned char *from, size_t from_length,
+ size_t *to_length)
+{
+ if (!conn)
+ return NULL;
+
+ resetPQExpBuffer(&conn->errorMessage);
+
+ return PQescapeByteaInternal(conn, from, from_length, to_length,
+ conn->std_strings,
+ (conn->sversion >= 90000));
+}
+
+unsigned char *
+PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
+{
+ return PQescapeByteaInternal(NULL, from, from_length, to_length,
+ static_std_strings,
+ false /* can't use hex */ );
+}
+
+
+#define ISFIRSTOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '3')
+#define ISOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '7')
+#define OCTVAL(CH) ((CH) - '0')
+
+/*
+ * PQunescapeBytea - converts the null terminated string representation
+ * of a bytea, strtext, into binary, filling a buffer. It returns a
+ * pointer to the buffer (or NULL on error), and the size of the
+ * buffer in retbuflen. The pointer may subsequently be used as an
+ * argument to the function PQfreemem.
+ *
+ * The following transformations are made:
+ * \\ == ASCII 92 == \
+ * \ooo == a byte whose value = ooo (ooo is an octal number)
+ * \x == x (x is any character not matched by the above transformations)
+ */
+unsigned char *
+PQunescapeBytea(const unsigned char *strtext, size_t *retbuflen)
+{
+ size_t strtextlen,
+ buflen;
+ unsigned char *buffer,
+ *tmpbuf;
+ size_t i,
+ j;
+
+ if (strtext == NULL)
+ return NULL;
+
+ strtextlen = strlen((const char *) strtext);
+
+ if (strtext[0] == '\\' && strtext[1] == 'x')
+ {
+ const unsigned char *s;
+ unsigned char *p;
+
+ buflen = (strtextlen - 2) / 2;
+ /* Avoid unportable malloc(0) */
+ buffer = (unsigned char *) malloc(buflen > 0 ? buflen : 1);
+ if (buffer == NULL)
+ return NULL;
+
+ s = strtext + 2;
+ p = buffer;
+ while (*s)
+ {
+ char v1,
+ v2;
+
+ /*
+ * Bad input is silently ignored. Note that this includes
+ * whitespace between hex pairs, which is allowed by byteain.
+ */
+ v1 = get_hex(*s++);
+ if (!*s || v1 == (char) -1)
+ continue;
+ v2 = get_hex(*s++);
+ if (v2 != (char) -1)
+ *p++ = (v1 << 4) | v2;
+ }
+
+ buflen = p - buffer;
+ }
+ else
+ {
+ /*
+ * Length of input is max length of output, but add one to avoid
+ * unportable malloc(0) if input is zero-length.
+ */
+ buffer = (unsigned char *) malloc(strtextlen + 1);
+ if (buffer == NULL)
+ return NULL;
+
+ for (i = j = 0; i < strtextlen;)
+ {
+ switch (strtext[i])
+ {
+ case '\\':
+ i++;
+ if (strtext[i] == '\\')
+ buffer[j++] = strtext[i++];
+ else
+ {
+ if ((ISFIRSTOCTDIGIT(strtext[i])) &&
+ (ISOCTDIGIT(strtext[i + 1])) &&
+ (ISOCTDIGIT(strtext[i + 2])))
+ {
+ int byte;
+
+ byte = OCTVAL(strtext[i++]);
+ byte = (byte << 3) + OCTVAL(strtext[i++]);
+ byte = (byte << 3) + OCTVAL(strtext[i++]);
+ buffer[j++] = byte;
+ }
+ }
+
+ /*
+ * Note: if we see '\' followed by something that isn't a
+ * recognized escape sequence, we loop around having done
+ * nothing except advance i. Therefore the something will
+ * be emitted as ordinary data on the next cycle. Corner
+ * case: '\' at end of string will just be discarded.
+ */
+ break;
+
+ default:
+ buffer[j++] = strtext[i++];
+ break;
+ }
+ }
+ buflen = j; /* buflen is the length of the dequoted data */
+ }
+
+ /* Shrink the buffer to be no larger than necessary */
+ /* +1 avoids unportable behavior when buflen==0 */
+ tmpbuf = realloc(buffer, buflen + 1);
+
+ /* It would only be a very brain-dead realloc that could fail, but... */
+ if (!tmpbuf)
+ {
+ free(buffer);
+ return NULL;
+ }
+
+ *retbuflen = buflen;
+ return tmpbuf;
+}