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Diffstat (limited to 'src/couchdb/couch_erl_driver.c')
| -rw-r--r-- | src/couchdb/couch_erl_driver.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/src/couchdb/couch_erl_driver.c b/src/couchdb/couch_erl_driver.c new file mode 100644 index 00000000..b5703f09 --- /dev/null +++ b/src/couchdb/couch_erl_driver.c @@ -0,0 +1,160 @@ +/* + +Licensed under the Apache License, Version 2.0 (the "License"); you may not use +this file except in compliance with the License. You may obtain a copy of the +License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software distributed +under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR +CONDITIONS OF ANY KIND, either express or implied. See the License for the +specific language governing permissions and limitations under the License. + +*/ + +// This file is the C port driver for Erlang. It provides a low overhead +// means of calling into C code, however unlike the Fabric engine, coding +// errors in this module can crash the entire Erlang server. + +#include "erl_driver.h" +#include "unicode/ucol.h" +#include "unicode/ucasemap.h" +#ifndef WIN32 +#include <string.h> // for memcpy +#endif + +typedef struct { + ErlDrvPort port; + UCollator* collNoCase; + UCollator* coll; +} couch_drv_data; + +static void couch_drv_stop(ErlDrvData data) +{ + couch_drv_data* pData = (couch_drv_data*)data; + if (pData->coll) { + ucol_close(pData->coll); + } + if (pData->collNoCase) { + ucol_close(pData->collNoCase); + } + driver_free((char*)pData); +} + +static ErlDrvData couch_drv_start(ErlDrvPort port, char *buff) +{ + UErrorCode status = U_ZERO_ERROR; + couch_drv_data* pData = (couch_drv_data*)driver_alloc(sizeof(couch_drv_data)); + + if (pData == NULL) + return ERL_DRV_ERROR_GENERAL; + + pData->port = port; + pData->coll = NULL; + pData->collNoCase = NULL; + pData->coll = ucol_open("", &status); + + if (U_FAILURE(status)) { + couch_drv_stop((ErlDrvData)pData); + return ERL_DRV_ERROR_GENERAL; + } + + pData->collNoCase = ucol_open("", &status); + if (U_FAILURE(status)) { + couch_drv_stop((ErlDrvData)pData); + return ERL_DRV_ERROR_GENERAL; + } + + ucol_setAttribute(pData->collNoCase, UCOL_STRENGTH, UCOL_PRIMARY, &status); + if (U_FAILURE(status)) { + couch_drv_stop((ErlDrvData)pData); + return ERL_DRV_ERROR_GENERAL; + } + + return (ErlDrvData)pData; +} + +static int return_control_result(void* pLocalResult, int localLen, char **ppRetBuf, int returnLen) +{ + if (*ppRetBuf == NULL || localLen > returnLen) { + *ppRetBuf = (char*)driver_alloc_binary(localLen); + if(*ppRetBuf == NULL) { + return -1; + } + } + memcpy(*ppRetBuf, pLocalResult, localLen); + return localLen; +} + +static int couch_drv_control(ErlDrvData drv_data, unsigned int command, const char *pBuf, + int bufLen, char **rbuf, int rlen) +{ + #define COLLATE 0 + #define COLLATE_NO_CASE 1 + + couch_drv_data* pData = (couch_drv_data*)drv_data; + + UErrorCode status = U_ZERO_ERROR; + int collResult; + char response; + UCharIterator iterA; + UCharIterator iterB; + int32_t length; + + // 2 strings are in the buffer, consecutively + // The strings begin first with a 32 bit integer byte length, then the actual + // string bytes follow. + + // first 32bits are the length + memcpy(&length, pBuf, sizeof(length)); + pBuf += sizeof(length); + + // point the iterator at it. + uiter_setUTF8(&iterA, pBuf, length); + + pBuf += length; // now on to string b + + // first 32bits are the length + memcpy(&length, pBuf, sizeof(length)); + pBuf += sizeof(length); + + // point the iterator at it. + uiter_setUTF8(&iterB, pBuf, length); + + if (command == COLLATE) + collResult = ucol_strcollIter(pData->coll, &iterA, &iterB, &status); + else if (command == COLLATE_NO_CASE) + collResult = ucol_strcollIter(pData->collNoCase, &iterA, &iterB, &status); + else + return -1; + + if (collResult < 0) + response = 0; //lt + else if (collResult > 0) + response = 1; //gt + else + response = 2; //eq + + return return_control_result(&response, sizeof(response), rbuf, rlen); +} + +ErlDrvEntry couch_driver_entry = { + NULL, /* F_PTR init, N/A */ + couch_drv_start, /* L_PTR start, called when port is opened */ + couch_drv_stop, /* F_PTR stop, called when port is closed */ + NULL, /* F_PTR output, called when erlang has sent */ + NULL, /* F_PTR ready_input, called when input descriptor ready */ + NULL, /* F_PTR ready_output, called when output descriptor ready */ + "couch_erl_driver", /* char *driver_name, the argument to open_port */ + NULL, /* F_PTR finish, called when unloaded */ + NULL, /* Not used */ + couch_drv_control, /* F_PTR control, port_command callback */ + NULL, /* F_PTR timeout, reserved */ + NULL /* F_PTR outputv, reserved */ +}; + +DRIVER_INIT(couch_erl_driver) /* must match name in driver_entry */ +{ + return &couch_driver_entry; +} |