android/sqlite3_android.cpp - platform/external/sqlite - Git at Google

 /*
  * Copyright (C) 2007 The Android Open Source Project
  *
  * 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.
  */

 #define LOG_TAG "sqlite3_android"

 #include <ctype.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include <unicode/ucol.h>
 #include <unicode/uiter.h>
 #include <unicode/ustring.h>
 #include <unicode/utypes.h>
 #include <cutils/log.h>
 #include <cutils/properties.h>

 #include "sqlite3_android.h"
 #include "PhoneNumberUtils.h"
 #include "PhonebookIndex.h"

 #define ENABLE_ANDROID_LOG 0
 #define SMALL_BUFFER_SIZE 10

 static int collate16(void *p, int n1, const void *v1, int n2, const void *v2)
 {
     UCollator *coll = (UCollator *) p;
     UCollationResult result = ucol_strcoll(coll, (const UChar *) v1, n1,
                                                  (const UChar *) v2, n2);

     if (result == UCOL_LESS) {
         return -1;
     } else if (result == UCOL_GREATER) {
         return 1;
     } else {
         return 0;
     }
 }

 static int collate8(void *p, int n1, const void *v1, int n2, const void *v2)
 {
     UCollator *coll = (UCollator *) p;
     UCharIterator i1, i2;
     UErrorCode status = U_ZERO_ERROR;

     uiter_setUTF8(&i1, (const char *) v1, n1);
     uiter_setUTF8(&i2, (const char *) v2, n2);

     UCollationResult result = ucol_strcollIter(coll, &i1, &i2, &status);

     if (U_FAILURE(status)) {
 //        LOGE("Collation iterator error: %d\n", status);
     }

     if (result == UCOL_LESS) {
         return -1;
     } else if (result == UCOL_GREATER) {
         return 1;
     } else {
         return 0;
     }
 }

 /**
  * Obtains the first UNICODE letter from the supplied string, normalizes and returns it.
  */
 static void get_phonebook_index(
     sqlite3_context * context, int argc, sqlite3_value ** argv)
 {
     if (argc != 2) {
       sqlite3_result_null(context);
       return;
     }

     char const * src = (char const *)sqlite3_value_text(argv[0]);
     char const * locale = (char const *)sqlite3_value_text(argv[1]);
     if (src == NULL || src[0] == 0 || locale == NULL) {
       sqlite3_result_null(context);
       return;
     }

     UCharIterator iter;
     uiter_setUTF8(&iter, src, -1);

     UBool isError = FALSE;
     UChar index[SMALL_BUFFER_SIZE];
     uint32_t len = android::GetPhonebookIndex(&iter, locale, index, sizeof(index), &isError);
     if (isError) {
       sqlite3_result_null(context);
       return;
     }

     uint32_t outlen = 0;
     uint8_t out[SMALL_BUFFER_SIZE];
     for (uint32_t i = 0; i < len; i++) {
       U8_APPEND(out, outlen, sizeof(out), index[i], isError);
       if (isError) {
         sqlite3_result_null(context);
         return;
       }
     }

     if (outlen == 0) {
       sqlite3_result_null(context);
       return;
     }

     sqlite3_result_text(context, (const char*)out, outlen, SQLITE_TRANSIENT);
 }

 static void phone_numbers_equal(sqlite3_context * context, int argc, sqlite3_value ** argv)
 {
     if (argc != 2 && argc != 3) {
         sqlite3_result_int(context, 0);
         return;
     }

     char const * num1 = (char const *)sqlite3_value_text(argv[0]);
     char const * num2 = (char const *)sqlite3_value_text(argv[1]);

     bool use_strict = false;
     if (argc == 3) {
         use_strict = (sqlite3_value_int(argv[2]) != 0);
     }

     if (num1 == NULL || num2 == NULL) {
         sqlite3_result_null(context);
         return;
     }

     bool equal =
         (use_strict ?
          android::phone_number_compare_strict(num1, num2) :
          android::phone_number_compare_loose(num1, num2));

     if (equal) {
         sqlite3_result_int(context, 1);
     } else {
         sqlite3_result_int(context, 0);
     }
 }

 #if ENABLE_ANDROID_LOG
 static void android_log(sqlite3_context * context, int argc, sqlite3_value ** argv)
 {
     char const * tag = "sqlite_trigger";
     char const * msg = "";
     int msgIndex = 0;

     switch (argc) {
         case 2:
             tag = (char const *)sqlite3_value_text(argv[0]);
             if (tag == NULL) {
                 tag = "sqlite_trigger";
             }
             msgIndex = 1;
         case 1:
             msg = (char const *)sqlite3_value_text(argv[msgIndex]);
             if (msg == NULL) {
                 msg = "";
             }
             LOG(LOG_INFO, tag, msg);
             sqlite3_result_int(context, 1);
             return;

         default:
             sqlite3_result_int(context, 0);
             return;
     }
 }
 #endif

 static void delete_file(sqlite3_context * context, int argc, sqlite3_value ** argv)
 {
     if (argc != 1) {
         sqlite3_result_int(context, 0);
         return;
     }

     char const * path = (char const *)sqlite3_value_text(argv[0]);
     char media_storage[PROPERTY_VALUE_MAX];
     char const * external_storage = getenv("EXTERNAL_STORAGE");
     if (path == NULL) {
         sqlite3_result_null(context);
         return;
     }

     property_get("ro.media.storage", media_storage, "");
     // path must match either ro.media.storage or EXTERNAL_STORAGE directory
     if ( !(media_storage[0] && strncmp(media_storage, path, strlen(media_storage)) == 0) &&
          !(external_storage && strncmp(external_storage, path, strlen(external_storage)) == 0)) {
         sqlite3_result_null(context);
         return;
     }
     if (strstr(path, "/../") != NULL) {
         sqlite3_result_null(context);
         return;
     }

     int err = unlink(path);
     if (err != -1) {
         // No error occured, return true
         sqlite3_result_int(context, 1);
     } else {
         // An error occured, return false
         sqlite3_result_int(context, 0);
     }
 }

 static void tokenize_auxdata_delete(void * data)
 {
     sqlite3_stmt * statement = (sqlite3_stmt *)data;
     sqlite3_finalize(statement);
 }

 static void base16Encode(char* dest, const char* src, uint32_t size)
 {
     static const char * BASE16_TABLE = "0123456789abcdef";
     for (uint32_t i = 0; i < size; i++) {
         char ch = *src++;
         *dest++ = BASE16_TABLE[ (ch & 0xf0) >> 4 ];
         *dest++ = BASE16_TABLE[ (ch & 0x0f)      ];
     }
 }

 struct SqliteUserData {
     sqlite3 * handle;
     UCollator* collator;
 };

 /**
  * This function is invoked as:
  *
  *  _TOKENIZE('<token_table>', <data_row_id>, <data>, <delimiter>,
  *             <use_token_index>, <data_tag>)
  *
  * If <use_token_index> is omitted, it is treated as 0.
  * If <data_tag> is omitted, it is treated as NULL.
  *
  * It will split <data> on each instance of <delimiter> and insert each token
  * into <token_table>. The following columns in <token_table> are used:
  * token TEXT, source INTEGER, token_index INTEGER, tag (any type)
  * The token_index column is not required if <use_token_index> is 0.
  * The tag column is not required if <data_tag> is NULL.
  *
  * One row is inserted for each token in <data>.
  * In each inserted row, 'source' is <data_row_id>.
  * In the first inserted row, 'token' is the hex collation key of
  * the entire <data> string, and 'token_index' is 0.
  * In each row I (where 1 <= I < N, and N is the number of tokens in <data>)
  * 'token' will be set to the hex collation key of the I:th token (0-based).
  * If <use_token_index> != 0, 'token_index' is set to I.
  * If <data_tag> is not NULL, 'tag' is set to <data_tag>.
  *
  * In other words, there will be one row for the entire string,
  * and one row for each token except the first one.
  *
  * The function returns the number of tokens generated.
  */
 static void tokenize(sqlite3_context * context, int argc, sqlite3_value ** argv)
 {
     //LOGD("enter tokenize");
     int err;
     int useTokenIndex = 0;
     int useDataTag = 0;

     if (!(argc >= 4 || argc <= 6)) {
         LOGE("Tokenize requires 4 to 6 arguments");
         sqlite3_result_null(context);
         return;
     }

     if (argc > 4) {
         useTokenIndex = sqlite3_value_int(argv[4]);
     }

     if (argc > 5) {
         useDataTag = (sqlite3_value_type(argv[5]) != SQLITE_NULL);
     }

     sqlite3 * handle = sqlite3_context_db_handle(context);
     UCollator* collator = (UCollator*)sqlite3_user_data(context);
     char const * tokenTable = (char const *)sqlite3_value_text(argv[0]);
     if (tokenTable == NULL) {
         LOGE("tokenTable null");
         sqlite3_result_null(context);
         return;
     }

     // Get or create the prepared statement for the insertions
     sqlite3_stmt * statement = (sqlite3_stmt *)sqlite3_get_auxdata(context, 0);
     if (!statement) {
         char const * tokenIndexCol = useTokenIndex ? ", token_index" : "";
         char const * tokenIndexParam = useTokenIndex ? ", ?" : "";
         char const * dataTagCol = useDataTag ? ", tag" : "";
         char const * dataTagParam = useDataTag ? ", ?" : "";
         char * sql = sqlite3_mprintf("INSERT INTO %s (token, source%s%s) VALUES (?, ?%s%s);",
                 tokenTable, tokenIndexCol, dataTagCol, tokenIndexParam, dataTagParam);
         err = sqlite3_prepare_v2(handle, sql, -1, &statement, NULL);
         sqlite3_free(sql);
         if (err) {
             LOGE("prepare failed");
             sqlite3_result_null(context);
             return;
         }
         // This binds the statement to the table it was compiled against, which is argv[0].
         // If this function is ever called with a different table the finalizer will be called
         // and sqlite3_get_auxdata() will return null above, forcing a recompile for the new table.
         sqlite3_set_auxdata(context, 0, statement, tokenize_auxdata_delete);
     } else {
         // Reset the cached statement so that binding the row ID will work properly
         sqlite3_reset(statement);
     }

     // Bind the row ID of the source row
     int64_t rowID = sqlite3_value_int64(argv[1]);
     err = sqlite3_bind_int64(statement, 2, rowID);
     if (err != SQLITE_OK) {
         LOGE("bind failed");
         sqlite3_result_null(context);
         return;
     }

     // Bind <data_tag> to the tag column
     if (useDataTag) {
         int dataTagParamIndex = useTokenIndex ? 4 : 3;
         err = sqlite3_bind_value(statement, dataTagParamIndex, argv[5]);
         if (err != SQLITE_OK) {
             LOGE("bind failed");
             sqlite3_result_null(context);
             return;
         }
     }

     // Get the raw bytes for the string to tokenize
     // the string will be modified by following code
     // however, sqlite did not reuse the string, so it is safe to not dup it
     UChar * origData = (UChar *)sqlite3_value_text16(argv[2]);
     if (origData == NULL) {
         sqlite3_result_null(context);
         return;
     }

     // Get the raw bytes for the delimiter
     const UChar * delim = (const UChar *)sqlite3_value_text16(argv[3]);
     if (delim == NULL) {
         LOGE("can't get delimiter");
         sqlite3_result_null(context);
         return;
     }

     UChar * token = NULL;
     UChar *state;
     int numTokens = 0;

     do {
         if (numTokens == 0) {
             token = origData;
         }

         // Reset the program so we can use it to perform the insert
         sqlite3_reset(statement);
         UErrorCode status = U_ZERO_ERROR;
         char keybuf[1024];
         uint32_t result = ucol_getSortKey(collator, token, -1, (uint8_t*)keybuf, sizeof(keybuf)-1);
         if (result > sizeof(keybuf)) {
             // TODO allocate memory for this super big string
             LOGE("ucol_getSortKey needs bigger buffer %d", result);
             break;
         }
         uint32_t keysize = result-1;
         uint32_t base16Size = keysize*2;
         char *base16buf = (char*)malloc(base16Size);
         base16Encode(base16buf, keybuf, keysize);
         err = sqlite3_bind_text(statement, 1, base16buf, base16Size, SQLITE_STATIC);

         if (err != SQLITE_OK) {
             LOGE(" sqlite3_bind_text16 error %d", err);
             free(base16buf);
             break;
         }

         if (useTokenIndex) {
             err = sqlite3_bind_int(statement, 3, numTokens);
             if (err != SQLITE_OK) {
                 LOGE(" sqlite3_bind_int error %d", err);
                 free(base16buf);
                 break;
             }
         }

         err = sqlite3_step(statement);
         free(base16buf);

         if (err != SQLITE_DONE) {
             LOGE(" sqlite3_step error %d", err);
             break;
         }
         numTokens++;
         if (numTokens == 1) {
             // first call
             u_strtok_r(origData, delim, &state);
         }
     } while ((token = u_strtok_r(NULL, delim, &state)) != NULL);
     sqlite3_result_int(context, numTokens);
 }

 static void localized_collator_dtor(UCollator* collator)
 {
     ucol_close(collator);
 }

 #define LOCALIZED_COLLATOR_NAME "LOCALIZED"

 // This collator may be removed in the near future, so you MUST not use now.
 #define PHONEBOOK_COLLATOR_NAME "PHONEBOOK"

 extern "C" int register_localized_collators(sqlite3* handle, const char* systemLocale, int utf16Storage)
 {
     int err;
     UErrorCode status = U_ZERO_ERROR;
     void* icudata;

     UCollator* collator = ucol_open(systemLocale, &status);
     if (U_FAILURE(status)) {
         return -1;
     }

     ucol_setAttribute(collator, UCOL_STRENGTH, UCOL_PRIMARY, &status);
     if (U_FAILURE(status)) {
         return -1;
     }

     status = U_ZERO_ERROR;
     char buf[1024];
     ucol_getShortDefinitionString(collator, NULL, buf, 1024, &status);

     if (utf16Storage) {
         err = sqlite3_create_collation_v2(handle, LOCALIZED_COLLATOR_NAME, SQLITE_UTF16, collator,
                 collate16, (void(*)(void*))localized_collator_dtor);
     } else {
         err = sqlite3_create_collation_v2(handle, LOCALIZED_COLLATOR_NAME, SQLITE_UTF8, collator,
                 collate8, (void(*)(void*))localized_collator_dtor);
     }

     if (err != SQLITE_OK) {
         return err;
     }

     // Register the _TOKENIZE function
     err = sqlite3_create_function(handle, "_TOKENIZE", 4, SQLITE_UTF16, collator, tokenize, NULL, NULL);
     if (err != SQLITE_OK) {
         return err;
     }
     err = sqlite3_create_function(handle, "_TOKENIZE", 5, SQLITE_UTF16, collator, tokenize, NULL, NULL);
     if (err != SQLITE_OK) {
         return err;
     }
     err = sqlite3_create_function(handle, "_TOKENIZE", 6, SQLITE_UTF16, collator, tokenize, NULL, NULL);
     if (err != SQLITE_OK) {
         return err;
     }


     //// PHONEBOOK_COLLATOR
     // The collator may be removed in the near future. Do not depend on it.
     // TODO: it might be better to have another function for registering phonebook collator.
     status = U_ZERO_ERROR;
     if (strcmp(systemLocale, "ja") == 0 || strcmp(systemLocale, "ja_JP") == 0) {
         collator = ucol_open("ja@collation=phonebook", &status);
     } else {
         collator = ucol_open(systemLocale, &status);
     }
     if (U_FAILURE(status)) {
         return -1;
     }

     status = U_ZERO_ERROR;
     ucol_setAttribute(collator, UCOL_STRENGTH, UCOL_PRIMARY, &status);
     if (U_FAILURE(status)) {
         return -1;
     }

     status = U_ZERO_ERROR;
     // ucol_getShortDefinitionString(collator, NULL, buf, 1024, &status);
     if (utf16Storage) {
         err = sqlite3_create_collation_v2(handle, PHONEBOOK_COLLATOR_NAME, SQLITE_UTF16, collator,
                 collate16, (void(*)(void*))localized_collator_dtor);
     } else {
         err = sqlite3_create_collation_v2(handle, PHONEBOOK_COLLATOR_NAME, SQLITE_UTF8, collator,
                 collate8, (void(*)(void*))localized_collator_dtor);
     }

     if (err != SQLITE_OK) {
         return err;
     }
     //// PHONEBOOK_COLLATOR

     return SQLITE_OK;
 }


 extern "C" int register_android_functions(sqlite3 * handle, int utf16Storage)
 {
     int err;
     UErrorCode status = U_ZERO_ERROR;

     UCollator * collator = ucol_open(NULL, &status);
     if (U_FAILURE(status)) {
         return -1;
     }

     if (utf16Storage) {
         // Note that text should be stored as UTF-16
         err = sqlite3_exec(handle, "PRAGMA encoding = 'UTF-16'", 0, 0, 0);
         if (err != SQLITE_OK) {
             return err;
         }

         // Register the UNICODE collation
         err = sqlite3_create_collation_v2(handle, "UNICODE", SQLITE_UTF16, collator, collate16,
                 (void(*)(void*))localized_collator_dtor);
     } else {
         err = sqlite3_create_collation_v2(handle, "UNICODE", SQLITE_UTF8, collator, collate8,
                 (void(*)(void*))localized_collator_dtor);
     }

     if (err != SQLITE_OK) {
         return err;
     }

     // Register the PHONE_NUM_EQUALS function
     err = sqlite3_create_function(
         handle, "PHONE_NUMBERS_EQUAL", 2,
         SQLITE_UTF8, NULL, phone_numbers_equal, NULL, NULL);
     if (err != SQLITE_OK) {
         return err;
     }

     // Register the PHONE_NUM_EQUALS function with an additional argument "use_strict"
     err = sqlite3_create_function(
         handle, "PHONE_NUMBERS_EQUAL", 3,
         SQLITE_UTF8, NULL, phone_numbers_equal, NULL, NULL);
     if (err != SQLITE_OK) {
         return err;
     }

     // Register the _DELETE_FILE function
     err = sqlite3_create_function(handle, "_DELETE_FILE", 1, SQLITE_UTF8, NULL, delete_file, NULL, NULL);
     if (err != SQLITE_OK) {
         return err;
     }

 #if ENABLE_ANDROID_LOG
     // Register the _LOG function
     err = sqlite3_create_function(handle, "_LOG", 1, SQLITE_UTF8, NULL, android_log, NULL, NULL);
     if (err != SQLITE_OK) {
         return err;
     }
 #endif

     // Register the GET_PHONEBOOK_INDEX function
     err = sqlite3_create_function(handle,
         "GET_PHONEBOOK_INDEX",
         2, SQLITE_UTF8, NULL,
         get_phonebook_index,
         NULL, NULL);
     if (err != SQLITE_OK) {
         return err;
     }

     return SQLITE_OK;
 }
	/*
	* Copyright (C) 2007 The Android Open Source Project
	*
	* 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.
	*/

	#define LOG_TAG "sqlite3_android"

	#include <ctype.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include <unicode/ucol.h>
	#include <unicode/uiter.h>
	#include <unicode/ustring.h>
	#include <unicode/utypes.h>
	#include <cutils/log.h>
	#include <cutils/properties.h>

	#include "sqlite3_android.h"
	#include "PhoneNumberUtils.h"
	#include "PhonebookIndex.h"

	#define ENABLE_ANDROID_LOG 0
	#define SMALL_BUFFER_SIZE 10

	static int collate16(void p, int n1, const void v1, int n2, const void *v2)
	{
	UCollator coll = (UCollator ) p;
	UCollationResult result = ucol_strcoll(coll, (const UChar *) v1, n1,
	(const UChar *) v2, n2);

	if (result == UCOL_LESS) {
	return -1;
	} else if (result == UCOL_GREATER) {
	return 1;
	} else {
	return 0;
	}
	}

	static int collate8(void p, int n1, const void v1, int n2, const void *v2)
	{
	UCollator coll = (UCollator ) p;
	UCharIterator i1, i2;
	UErrorCode status = U_ZERO_ERROR;

	uiter_setUTF8(&i1, (const char *) v1, n1);
	uiter_setUTF8(&i2, (const char *) v2, n2);

	UCollationResult result = ucol_strcollIter(coll, &i1, &i2, &status);

	if (U_FAILURE(status)) {
	// LOGE("Collation iterator error: %d\n", status);
	}

	if (result == UCOL_LESS) {
	return -1;
	} else if (result == UCOL_GREATER) {
	return 1;
	} else {
	return 0;
	}
	}

	/**
	* Obtains the first UNICODE letter from the supplied string, normalizes and returns it.
	*/
	static void get_phonebook_index(
	sqlite3_context * context, int argc, sqlite3_value ** argv)
	{
	if (argc != 2) {
	sqlite3_result_null(context);
	return;
	}

	char const * src = (char const *)sqlite3_value_text(argv[0]);
	char const * locale = (char const *)sqlite3_value_text(argv[1]);
	if (src == NULL \|\| src[0] == 0 \|\| locale == NULL) {
	sqlite3_result_null(context);
	return;
	}

	UCharIterator iter;
	uiter_setUTF8(&iter, src, -1);

	UBool isError = FALSE;
	UChar index[SMALL_BUFFER_SIZE];
	uint32_t len = android::GetPhonebookIndex(&iter, locale, index, sizeof(index), &isError);
	if (isError) {
	sqlite3_result_null(context);
	return;
	}

	uint32_t outlen = 0;
	uint8_t out[SMALL_BUFFER_SIZE];
	for (uint32_t i = 0; i < len; i++) {
	U8_APPEND(out, outlen, sizeof(out), index[i], isError);
	if (isError) {
	sqlite3_result_null(context);
	return;
	}
	}

	if (outlen == 0) {
	sqlite3_result_null(context);
	return;
	}

	sqlite3_result_text(context, (const char*)out, outlen, SQLITE_TRANSIENT);
	}

	static void phone_numbers_equal(sqlite3_context * context, int argc, sqlite3_value ** argv)
	{
	if (argc != 2 && argc != 3) {
	sqlite3_result_int(context, 0);
	return;
	}

	char const * num1 = (char const *)sqlite3_value_text(argv[0]);
	char const * num2 = (char const *)sqlite3_value_text(argv[1]);

	bool use_strict = false;
	if (argc == 3) {
	use_strict = (sqlite3_value_int(argv[2]) != 0);
	}

	if (num1 == NULL \|\| num2 == NULL) {
	sqlite3_result_null(context);
	return;
	}

	bool equal =
	(use_strict ?
	android::phone_number_compare_strict(num1, num2) :
	android::phone_number_compare_loose(num1, num2));

	if (equal) {
	sqlite3_result_int(context, 1);
	} else {
	sqlite3_result_int(context, 0);
	}
	}

	#if ENABLE_ANDROID_LOG
	static void android_log(sqlite3_context * context, int argc, sqlite3_value ** argv)
	{
	char const * tag = "sqlite_trigger";
	char const * msg = "";
	int msgIndex = 0;

	switch (argc) {
	case 2:
	tag = (char const *)sqlite3_value_text(argv[0]);
	if (tag == NULL) {
	tag = "sqlite_trigger";
	}
	msgIndex = 1;
	case 1:
	msg = (char const *)sqlite3_value_text(argv[msgIndex]);
	if (msg == NULL) {
	msg = "";
	}
	LOG(LOG_INFO, tag, msg);
	sqlite3_result_int(context, 1);
	return;

	default:
	sqlite3_result_int(context, 0);
	return;
	}
	}
	#endif

	static void delete_file(sqlite3_context * context, int argc, sqlite3_value ** argv)
	{
	if (argc != 1) {
	sqlite3_result_int(context, 0);
	return;
	}

	char const * path = (char const *)sqlite3_value_text(argv[0]);
	char media_storage[PROPERTY_VALUE_MAX];
	char const * external_storage = getenv("EXTERNAL_STORAGE");
	if (path == NULL) {
	sqlite3_result_null(context);
	return;
	}

	property_get("ro.media.storage", media_storage, "");
	// path must match either ro.media.storage or EXTERNAL_STORAGE directory
	if ( !(media_storage[0] && strncmp(media_storage, path, strlen(media_storage)) == 0) &&
	!(external_storage && strncmp(external_storage, path, strlen(external_storage)) == 0)) {
	sqlite3_result_null(context);
	return;
	}
	if (strstr(path, "/../") != NULL) {
	sqlite3_result_null(context);
	return;
	}

	int err = unlink(path);
	if (err != -1) {
	// No error occured, return true
	sqlite3_result_int(context, 1);
	} else {
	// An error occured, return false
	sqlite3_result_int(context, 0);
	}
	}

	static void tokenize_auxdata_delete(void * data)
	{
	sqlite3_stmt * statement = (sqlite3_stmt *)data;
	sqlite3_finalize(statement);
	}

	static void base16Encode(char* dest, const char* src, uint32_t size)
	{
	static const char * BASE16_TABLE = "0123456789abcdef";
	for (uint32_t i = 0; i < size; i++) {
	char ch = *src++;
	*dest++ = BASE16_TABLE[ (ch & 0xf0) >> 4 ];
	*dest++ = BASE16_TABLE[ (ch & 0x0f) ];
	}
	}

	struct SqliteUserData {
	sqlite3 * handle;
	UCollator* collator;
	};

	/**
	* This function is invoked as:
	*
	* _TOKENIZE('<token_table>', <data_row_id>, <data>, <delimiter>,
	* <use_token_index>, <data_tag>)
	*
	* If <use_token_index> is omitted, it is treated as 0.
	* If <data_tag> is omitted, it is treated as NULL.
	*
	* It will split <data> on each instance of <delimiter> and insert each token
	* into <token_table>. The following columns in <token_table> are used:
	* token TEXT, source INTEGER, token_index INTEGER, tag (any type)
	* The token_index column is not required if <use_token_index> is 0.
	* The tag column is not required if <data_tag> is NULL.
	*
	* One row is inserted for each token in <data>.
	* In each inserted row, 'source' is <data_row_id>.
	* In the first inserted row, 'token' is the hex collation key of
	* the entire <data> string, and 'token_index' is 0.
	* In each row I (where 1 <= I < N, and N is the number of tokens in <data>)
	* 'token' will be set to the hex collation key of the I:th token (0-based).
	* If <use_token_index> != 0, 'token_index' is set to I.
	* If <data_tag> is not NULL, 'tag' is set to <data_tag>.
	*
	* In other words, there will be one row for the entire string,
	* and one row for each token except the first one.
	*
	* The function returns the number of tokens generated.
	*/
	static void tokenize(sqlite3_context * context, int argc, sqlite3_value ** argv)
	{
	//LOGD("enter tokenize");
	int err;
	int useTokenIndex = 0;
	int useDataTag = 0;

	if (!(argc >= 4 \|\| argc <= 6)) {
	LOGE("Tokenize requires 4 to 6 arguments");
	sqlite3_result_null(context);
	return;
	}

	if (argc > 4) {
	useTokenIndex = sqlite3_value_int(argv[4]);
	}

	if (argc > 5) {
	useDataTag = (sqlite3_value_type(argv[5]) != SQLITE_NULL);
	}

	sqlite3 * handle = sqlite3_context_db_handle(context);
	UCollator* collator = (UCollator*)sqlite3_user_data(context);
	char const * tokenTable = (char const *)sqlite3_value_text(argv[0]);
	if (tokenTable == NULL) {
	LOGE("tokenTable null");
	sqlite3_result_null(context);
	return;
	}

	// Get or create the prepared statement for the insertions
	sqlite3_stmt * statement = (sqlite3_stmt *)sqlite3_get_auxdata(context, 0);
	if (!statement) {
	char const * tokenIndexCol = useTokenIndex ? ", token_index" : "";
	char const * tokenIndexParam = useTokenIndex ? ", ?" : "";
	char const * dataTagCol = useDataTag ? ", tag" : "";
	char const * dataTagParam = useDataTag ? ", ?" : "";
	char * sql = sqlite3_mprintf("INSERT INTO %s (token, source%s%s) VALUES (?, ?%s%s);",
	tokenTable, tokenIndexCol, dataTagCol, tokenIndexParam, dataTagParam);
	err = sqlite3_prepare_v2(handle, sql, -1, &statement, NULL);
	sqlite3_free(sql);
	if (err) {
	LOGE("prepare failed");
	sqlite3_result_null(context);
	return;
	}
	// This binds the statement to the table it was compiled against, which is argv[0].
	// If this function is ever called with a different table the finalizer will be called
	// and sqlite3_get_auxdata() will return null above, forcing a recompile for the new table.
	sqlite3_set_auxdata(context, 0, statement, tokenize_auxdata_delete);
	} else {
	// Reset the cached statement so that binding the row ID will work properly
	sqlite3_reset(statement);
	}

	// Bind the row ID of the source row
	int64_t rowID = sqlite3_value_int64(argv[1]);
	err = sqlite3_bind_int64(statement, 2, rowID);
	if (err != SQLITE_OK) {
	LOGE("bind failed");
	sqlite3_result_null(context);
	return;
	}

	// Bind <data_tag> to the tag column
	if (useDataTag) {
	int dataTagParamIndex = useTokenIndex ? 4 : 3;
	err = sqlite3_bind_value(statement, dataTagParamIndex, argv[5]);
	if (err != SQLITE_OK) {
	LOGE("bind failed");
	sqlite3_result_null(context);
	return;
	}
	}

	// Get the raw bytes for the string to tokenize
	// the string will be modified by following code
	// however, sqlite did not reuse the string, so it is safe to not dup it
	UChar * origData = (UChar *)sqlite3_value_text16(argv[2]);
	if (origData == NULL) {
	sqlite3_result_null(context);
	return;
	}

	// Get the raw bytes for the delimiter
	const UChar * delim = (const UChar *)sqlite3_value_text16(argv[3]);
	if (delim == NULL) {
	LOGE("can't get delimiter");
	sqlite3_result_null(context);
	return;
	}

	UChar * token = NULL;
	UChar *state;
	int numTokens = 0;

	do {
	if (numTokens == 0) {
	token = origData;
	}

	// Reset the program so we can use it to perform the insert
	sqlite3_reset(statement);
	UErrorCode status = U_ZERO_ERROR;
	char keybuf[1024];
	uint32_t result = ucol_getSortKey(collator, token, -1, (uint8_t*)keybuf, sizeof(keybuf)-1);
	if (result > sizeof(keybuf)) {
	// TODO allocate memory for this super big string
	LOGE("ucol_getSortKey needs bigger buffer %d", result);
	break;
	}
	uint32_t keysize = result-1;
	uint32_t base16Size = keysize*2;
	char base16buf = (char)malloc(base16Size);
	base16Encode(base16buf, keybuf, keysize);
	err = sqlite3_bind_text(statement, 1, base16buf, base16Size, SQLITE_STATIC);

	if (err != SQLITE_OK) {
	LOGE(" sqlite3_bind_text16 error %d", err);
	free(base16buf);
	break;
	}

	if (useTokenIndex) {
	err = sqlite3_bind_int(statement, 3, numTokens);
	if (err != SQLITE_OK) {
	LOGE(" sqlite3_bind_int error %d", err);
	free(base16buf);
	break;
	}
	}

	err = sqlite3_step(statement);
	free(base16buf);

	if (err != SQLITE_DONE) {
	LOGE(" sqlite3_step error %d", err);
	break;
	}
	numTokens++;
	if (numTokens == 1) {
	// first call
	u_strtok_r(origData, delim, &state);
	}
	} while ((token = u_strtok_r(NULL, delim, &state)) != NULL);
	sqlite3_result_int(context, numTokens);
	}

	static void localized_collator_dtor(UCollator* collator)
	{
	ucol_close(collator);
	}

	#define LOCALIZED_COLLATOR_NAME "LOCALIZED"

	// This collator may be removed in the near future, so you MUST not use now.
	#define PHONEBOOK_COLLATOR_NAME "PHONEBOOK"

	extern "C" int register_localized_collators(sqlite3* handle, const char* systemLocale, int utf16Storage)
	{
	int err;
	UErrorCode status = U_ZERO_ERROR;
	void* icudata;

	UCollator* collator = ucol_open(systemLocale, &status);
	if (U_FAILURE(status)) {
	return -1;
	}

	ucol_setAttribute(collator, UCOL_STRENGTH, UCOL_PRIMARY, &status);
	if (U_FAILURE(status)) {
	return -1;
	}

	status = U_ZERO_ERROR;
	char buf[1024];
	ucol_getShortDefinitionString(collator, NULL, buf, 1024, &status);

	if (utf16Storage) {
	err = sqlite3_create_collation_v2(handle, LOCALIZED_COLLATOR_NAME, SQLITE_UTF16, collator,
	collate16, (void()(void))localized_collator_dtor);
	} else {
	err = sqlite3_create_collation_v2(handle, LOCALIZED_COLLATOR_NAME, SQLITE_UTF8, collator,
	collate8, (void()(void))localized_collator_dtor);
	}

	if (err != SQLITE_OK) {
	return err;
	}

	// Register the _TOKENIZE function
	err = sqlite3_create_function(handle, "_TOKENIZE", 4, SQLITE_UTF16, collator, tokenize, NULL, NULL);
	if (err != SQLITE_OK) {
	return err;
	}
	err = sqlite3_create_function(handle, "_TOKENIZE", 5, SQLITE_UTF16, collator, tokenize, NULL, NULL);
	if (err != SQLITE_OK) {
	return err;
	}
	err = sqlite3_create_function(handle, "_TOKENIZE", 6, SQLITE_UTF16, collator, tokenize, NULL, NULL);
	if (err != SQLITE_OK) {
	return err;
	}


	//// PHONEBOOK_COLLATOR
	// The collator may be removed in the near future. Do not depend on it.
	// TODO: it might be better to have another function for registering phonebook collator.
	status = U_ZERO_ERROR;
	if (strcmp(systemLocale, "ja") == 0 \|\| strcmp(systemLocale, "ja_JP") == 0) {
	collator = ucol_open("ja@collation=phonebook", &status);
	} else {
	collator = ucol_open(systemLocale, &status);
	}
	if (U_FAILURE(status)) {
	return -1;
	}

	status = U_ZERO_ERROR;
	ucol_setAttribute(collator, UCOL_STRENGTH, UCOL_PRIMARY, &status);
	if (U_FAILURE(status)) {
	return -1;
	}

	status = U_ZERO_ERROR;
	// ucol_getShortDefinitionString(collator, NULL, buf, 1024, &status);
	if (utf16Storage) {
	err = sqlite3_create_collation_v2(handle, PHONEBOOK_COLLATOR_NAME, SQLITE_UTF16, collator,
	collate16, (void()(void))localized_collator_dtor);
	} else {
	err = sqlite3_create_collation_v2(handle, PHONEBOOK_COLLATOR_NAME, SQLITE_UTF8, collator,
	collate8, (void()(void))localized_collator_dtor);
	}

	if (err != SQLITE_OK) {
	return err;
	}
	//// PHONEBOOK_COLLATOR

	return SQLITE_OK;
	}


	extern "C" int register_android_functions(sqlite3 * handle, int utf16Storage)
	{
	int err;
	UErrorCode status = U_ZERO_ERROR;

	UCollator * collator = ucol_open(NULL, &status);
	if (U_FAILURE(status)) {
	return -1;
	}

	if (utf16Storage) {
	// Note that text should be stored as UTF-16
	err = sqlite3_exec(handle, "PRAGMA encoding = 'UTF-16'", 0, 0, 0);
	if (err != SQLITE_OK) {
	return err;
	}

	// Register the UNICODE collation
	err = sqlite3_create_collation_v2(handle, "UNICODE", SQLITE_UTF16, collator, collate16,
	(void()(void))localized_collator_dtor);
	} else {
	err = sqlite3_create_collation_v2(handle, "UNICODE", SQLITE_UTF8, collator, collate8,
	(void()(void))localized_collator_dtor);
	}

	if (err != SQLITE_OK) {
	return err;
	}

	// Register the PHONE_NUM_EQUALS function
	err = sqlite3_create_function(
	handle, "PHONE_NUMBERS_EQUAL", 2,
	SQLITE_UTF8, NULL, phone_numbers_equal, NULL, NULL);
	if (err != SQLITE_OK) {
	return err;
	}

	// Register the PHONE_NUM_EQUALS function with an additional argument "use_strict"
	err = sqlite3_create_function(
	handle, "PHONE_NUMBERS_EQUAL", 3,
	SQLITE_UTF8, NULL, phone_numbers_equal, NULL, NULL);
	if (err != SQLITE_OK) {
	return err;
	}

	// Register the _DELETE_FILE function
	err = sqlite3_create_function(handle, "_DELETE_FILE", 1, SQLITE_UTF8, NULL, delete_file, NULL, NULL);
	if (err != SQLITE_OK) {
	return err;
	}

	#if ENABLE_ANDROID_LOG
	// Register the _LOG function
	err = sqlite3_create_function(handle, "_LOG", 1, SQLITE_UTF8, NULL, android_log, NULL, NULL);
	if (err != SQLITE_OK) {
	return err;
	}
	#endif

	// Register the GET_PHONEBOOK_INDEX function
	err = sqlite3_create_function(handle,
	"GET_PHONEBOOK_INDEX",
	2, SQLITE_UTF8, NULL,
	get_phonebook_index,
	NULL, NULL);
	if (err != SQLITE_OK) {
	return err;
	}

	return SQLITE_OK;
	}