/*------------------------------------------------------------------------- * * 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 #include #include #ifdef WIN32 #include "win32.h" #else #include #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 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 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; }