[sql] Import SQLite 3.17.0.

third_party/sqlite/src/ext/fts5/fts5_test_tok.c

+/*
+** 2013 Apr 22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code for the "fts5tokenize" virtual table module.
+** An fts5tokenize virtual table is created as follows:
+**
+**   CREATE VIRTUAL TABLE <tbl> USING fts5tokenize(
+**       <tokenizer-name>, <arg-1>, ...
+**   );
+**
+** The table created has the following schema:
+**
+**   CREATE TABLE <tbl>(input HIDDEN, token, start, end, position)
+**
+** When queried, the query must include a WHERE clause of type:
+**
+**   input = <string>
+**
+** The virtual table module tokenizes this <string>, using the FTS3 
+** tokenizer specified by the arguments to the CREATE VIRTUAL TABLE 
+** statement and returns one row for each token in the result. With
+** fields set as follows:
+**
+**   input:   Always set to a copy of <string>
+**   token:   A token from the input.
+**   start:   Byte offset of the token within the input <string>.
+**   end:     Byte offset of the byte immediately following the end of the
+**            token within the input string.
+**   pos:     Token offset of token within input.
+**
+*/
+#if defined(SQLITE_TEST) && defined(SQLITE_ENABLE_FTS5)
+
+#include <fts5.h>
+#include <string.h>
+#include <assert.h>
+
+typedef struct Fts5tokTable Fts5tokTable;
+typedef struct Fts5tokCursor Fts5tokCursor;
+typedef struct Fts5tokRow Fts5tokRow;
+
+/*
+** Virtual table structure.
+*/
+struct Fts5tokTable {
+  sqlite3_vtab base;              /* Base class used by SQLite core */
+  fts5_tokenizer tok;             /* Tokenizer functions */
+  Fts5Tokenizer *pTok;            /* Tokenizer instance */
+};
+
+/*
+** A container for a rows values.
+*/
+struct Fts5tokRow {
+  char *zToken;
+  int iStart;
+  int iEnd;
+  int iPos;
+};
+
+/*
+** Virtual table cursor structure.
+*/
+struct Fts5tokCursor {
+  sqlite3_vtab_cursor base;       /* Base class used by SQLite core */
+  int iRowid;                     /* Current 'rowid' value */
+  char *zInput;                   /* Input string */
+  int nRow;                       /* Number of entries in aRow[] */
+  Fts5tokRow *aRow;               /* Array of rows to return */
+};
+
+static void fts5tokDequote(char *z){
+  char q = z[0];
+
+  if( q=='[' || q=='\'' || q=='"' || q=='`' ){
+    int iIn = 1;
+    int iOut = 0;
+    if( q=='[' ) q = ']';  
+
+    while( z[iIn] ){
+      if( z[iIn]==q ){
+        if( z[iIn+1]!=q ){
+          /* Character iIn was the close quote. */
+          iIn++;
+          break;
+        }else{
+          /* Character iIn and iIn+1 form an escaped quote character. Skip
+          ** the input cursor past both and copy a single quote character 
+          ** to the output buffer. */
+          iIn += 2;
+          z[iOut++] = q;
+        }
+      }else{
+        z[iOut++] = z[iIn++];
+      }
+    }
+
+    z[iOut] = '\0';
+  }
+}
+
+/*
+** The second argument, argv[], is an array of pointers to nul-terminated
+** strings. This function makes a copy of the array and strings into a 
+** single block of memory. It then dequotes any of the strings that appear
+** to be quoted.
+**
+** If successful, output parameter *pazDequote is set to point at the
+** array of dequoted strings and SQLITE_OK is returned. The caller is
+** responsible for eventually calling sqlite3_free() to free the array
+** in this case. Or, if an error occurs, an SQLite error code is returned.
+** The final value of *pazDequote is undefined in this case.
+*/
+static int fts5tokDequoteArray(
+  int argc,                       /* Number of elements in argv[] */
+  const char * const *argv,       /* Input array */
+  char ***pazDequote              /* Output array */
+){
+  int rc = SQLITE_OK;             /* Return code */
+  if( argc==0 ){
+    *pazDequote = 0;
+  }else{
+    int i;
+    int nByte = 0;
+    char **azDequote;
+
+    for(i=0; i<argc; i++){
+      nByte += (int)(strlen(argv[i]) + 1);
+    }
+
+    *pazDequote = azDequote = sqlite3_malloc(sizeof(char *)*argc + nByte);
+    if( azDequote==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      char *pSpace = (char *)&azDequote[argc];
+      for(i=0; i<argc; i++){
+        int n = (int)strlen(argv[i]);
+        azDequote[i] = pSpace;
+        memcpy(pSpace, argv[i], n+1);
+        fts5tokDequote(pSpace);
+        pSpace += (n+1);
+      }
+    }
+  }
+
+  return rc;
+}
+
+/*
+** Schema of the tokenizer table.
+*/
+#define FTS3_TOK_SCHEMA "CREATE TABLE x(input HIDDEN, token, start, end, position)"
+
+/*
+** This function does all the work for both the xConnect and xCreate methods.
+** These tables have no persistent representation of their own, so xConnect
+** and xCreate are identical operations.
+**
+**   argv[0]: module name
+**   argv[1]: database name 
+**   argv[2]: table name
+**   argv[3]: first argument (tokenizer name)
+*/
+static int fts5tokConnectMethod(
+  sqlite3 *db,                    /* Database connection */
+  void *pCtx,                     /* Pointer to fts5_api object */
+  int argc,                       /* Number of elements in argv array */
+  const char * const *argv,       /* xCreate/xConnect argument array */
+  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
+  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
+){
+  fts5_api *pApi = (fts5_api*)pCtx;
+  Fts5tokTable *pTab = 0;
+  int rc;
+  char **azDequote = 0;
+  int nDequote;
+
+  rc = sqlite3_declare_vtab(db, 
+       "CREATE TABLE x(input HIDDEN, token, start, end, position)"
+  );
+
+  if( rc==SQLITE_OK ){
+    nDequote = argc-3;
+    rc = fts5tokDequoteArray(nDequote, &argv[3], &azDequote);
+  }
+
+  if( rc==SQLITE_OK ){
+    pTab = (Fts5tokTable*)sqlite3_malloc(sizeof(Fts5tokTable));
+    if( pTab==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memset(pTab, 0, sizeof(Fts5tokTable));
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    void *pTokCtx = 0;
+    const char *zModule = 0;
+    if( nDequote>0 ){
+      zModule = azDequote[0];
+    }
+
+    rc = pApi->xFindTokenizer(pApi, zModule, &pTokCtx, &pTab->tok);
+    if( rc==SQLITE_OK ){
+      const char **azArg = (const char **)&azDequote[1];
+      int nArg = nDequote>0 ? nDequote-1 : 0;
+      rc = pTab->tok.xCreate(pTokCtx, azArg, nArg, &pTab->pTok);
+    }
+  }
+
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(pTab);
+    pTab = 0;
+  }
+
+  *ppVtab = (sqlite3_vtab*)pTab;
+  sqlite3_free(azDequote);
+  return rc;
+}
+
+/*
+** This function does the work for both the xDisconnect and xDestroy methods.
+** These tables have no persistent representation of their own, so xDisconnect
+** and xDestroy are identical operations.
+*/
+static int fts5tokDisconnectMethod(sqlite3_vtab *pVtab){
+  Fts5tokTable *pTab = (Fts5tokTable *)pVtab;
+  if( pTab->pTok ){
+    pTab->tok.xDelete(pTab->pTok);
+  }
+  sqlite3_free(pTab);
+  return SQLITE_OK;
+}
+
+/*
+** xBestIndex - Analyze a WHERE and ORDER BY clause.
+*/
+static int fts5tokBestIndexMethod(
+  sqlite3_vtab *pVTab, 
+  sqlite3_index_info *pInfo
+){
+  int i;
+
+  for(i=0; i<pInfo->nConstraint; i++){
+    if( pInfo->aConstraint[i].usable 
+     && pInfo->aConstraint[i].iColumn==0 
+     && pInfo->aConstraint[i].op==SQLITE_INDEX_CONSTRAINT_EQ 
+    ){
+      pInfo->idxNum = 1;
+      pInfo->aConstraintUsage[i].argvIndex = 1;
+      pInfo->aConstraintUsage[i].omit = 1;
+      pInfo->estimatedCost = 1;
+      return SQLITE_OK;
+    }
+  }
+
+  pInfo->idxNum = 0;
+  assert( pInfo->estimatedCost>1000000.0 );
+
+  return SQLITE_OK;
+}
+
+/*
+** xOpen - Open a cursor.
+*/
+static int fts5tokOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
+  Fts5tokCursor *pCsr;
+
+  pCsr = (Fts5tokCursor *)sqlite3_malloc(sizeof(Fts5tokCursor));
+  if( pCsr==0 ){
+    return SQLITE_NOMEM;
+  }
+  memset(pCsr, 0, sizeof(Fts5tokCursor));
+
+  *ppCsr = (sqlite3_vtab_cursor *)pCsr;
+  return SQLITE_OK;
+}
+
+/*
+** Reset the tokenizer cursor passed as the only argument. As if it had
+** just been returned by fts5tokOpenMethod().
+*/
+static void fts5tokResetCursor(Fts5tokCursor *pCsr){
+  int i;
+  for(i=0; i<pCsr->nRow; i++){
+    sqlite3_free(pCsr->aRow[i].zToken);
+  }
+  sqlite3_free(pCsr->zInput);
+  sqlite3_free(pCsr->aRow);
+  pCsr->zInput = 0;
+  pCsr->aRow = 0;
+  pCsr->nRow = 0;
+  pCsr->iRowid = 0;
+}
+
+/*
+** xClose - Close a cursor.
+*/
+static int fts5tokCloseMethod(sqlite3_vtab_cursor *pCursor){
+  Fts5tokCursor *pCsr = (Fts5tokCursor *)pCursor;
+  fts5tokResetCursor(pCsr);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/*
+** xNext - Advance the cursor to the next row, if any.
+*/
+static int fts5tokNextMethod(sqlite3_vtab_cursor *pCursor){
+  Fts5tokCursor *pCsr = (Fts5tokCursor *)pCursor;
+  pCsr->iRowid++;
+  return SQLITE_OK;
+}
+
+static int fts5tokCb(
+  void *pCtx,         /* Pointer to Fts5tokCursor */
+  int tflags,         /* Mask of FTS5_TOKEN_* flags */
+  const char *pToken, /* Pointer to buffer containing token */
+  int nToken,         /* Size of token in bytes */
+  int iStart,         /* Byte offset of token within input text */
+  int iEnd            /* Byte offset of end of token within input text */
+){
+  Fts5tokCursor *pCsr = (Fts5tokCursor*)pCtx;
+  Fts5tokRow *pRow;
+
+  if( (pCsr->nRow & (pCsr->nRow-1))==0 ){
+    int nNew = pCsr->nRow ? pCsr->nRow*2 : 32;
+    Fts5tokRow *aNew;
+    aNew = (Fts5tokRow*)sqlite3_realloc(pCsr->aRow, nNew*sizeof(Fts5tokRow));
+    if( aNew==0 ) return SQLITE_NOMEM;
+    memset(&aNew[pCsr->nRow], 0, sizeof(Fts5tokRow)*(nNew-pCsr->nRow));
+    pCsr->aRow = aNew;
+  }
+
+  pRow = &pCsr->aRow[pCsr->nRow];
+  pRow->iStart = iStart;
+  pRow->iEnd = iEnd;
+  if( pCsr->nRow ){
+    pRow->iPos = pRow[-1].iPos + ((tflags & FTS5_TOKEN_COLOCATED) ? 0 : 1);
+  }
+  pRow->zToken = sqlite3_malloc(nToken+1);
+  if( pRow->zToken==0 ) return SQLITE_NOMEM;
+  memcpy(pRow->zToken, pToken, nToken);
+  pRow->zToken[nToken] = 0;
+  pCsr->nRow++;
+
+  return SQLITE_OK;
+}
+
+/*
+** xFilter - Initialize a cursor to point at the start of its data.
+*/
+static int fts5tokFilterMethod(
+  sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */
+  int idxNum,                     /* Strategy index */
+  const char *idxStr,             /* Unused */
+  int nVal,                       /* Number of elements in apVal */
+  sqlite3_value **apVal           /* Arguments for the indexing scheme */
+){
+  int rc = SQLITE_ERROR;
+  Fts5tokCursor *pCsr = (Fts5tokCursor *)pCursor;
+  Fts5tokTable *pTab = (Fts5tokTable *)(pCursor->pVtab);
+
+  fts5tokResetCursor(pCsr);
+  if( idxNum==1 ){
+    const char *zByte = (const char *)sqlite3_value_text(apVal[0]);
+    int nByte = sqlite3_value_bytes(apVal[0]);
+    pCsr->zInput = sqlite3_malloc(nByte+1);
+    if( pCsr->zInput==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      memcpy(pCsr->zInput, zByte, nByte);
+      pCsr->zInput[nByte] = 0;
+      rc = pTab->tok.xTokenize(
+          pTab->pTok, (void*)pCsr, 0, zByte, nByte, fts5tokCb
+      );
+    }
+  }
+
+  if( rc!=SQLITE_OK ) return rc;
+  return fts5tokNextMethod(pCursor);
+}
+
+/*
+** xEof - Return true if the cursor is at EOF, or false otherwise.
+*/
+static int fts5tokEofMethod(sqlite3_vtab_cursor *pCursor){
+  Fts5tokCursor *pCsr = (Fts5tokCursor *)pCursor;
+  return (pCsr->iRowid>pCsr->nRow);
+}
+
+/*
+** xColumn - Return a column value.
+*/
+static int fts5tokColumnMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
+  int iCol                        /* Index of column to read value from */
+){
+  Fts5tokCursor *pCsr = (Fts5tokCursor *)pCursor;
+  Fts5tokRow *pRow = &pCsr->aRow[pCsr->iRowid-1];
+
+  /* CREATE TABLE x(input, token, start, end, position) */
+  switch( iCol ){
+    case 0:
+      sqlite3_result_text(pCtx, pCsr->zInput, -1, SQLITE_TRANSIENT);
+      break;
+    case 1:
+      sqlite3_result_text(pCtx, pRow->zToken, -1, SQLITE_TRANSIENT);
+      break;
+    case 2:
+      sqlite3_result_int(pCtx, pRow->iStart);
+      break;
+    case 3:
+      sqlite3_result_int(pCtx, pRow->iEnd);
+      break;
+    default:
+      assert( iCol==4 );
+      sqlite3_result_int(pCtx, pRow->iPos);
+      break;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** xRowid - Return the current rowid for the cursor.
+*/
+static int fts5tokRowidMethod(
+  sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
+  sqlite_int64 *pRowid            /* OUT: Rowid value */
+){
+  Fts5tokCursor *pCsr = (Fts5tokCursor *)pCursor;
+  *pRowid = (sqlite3_int64)pCsr->iRowid;
+  return SQLITE_OK;
+}
+
+/*
+** Register the fts5tok module with database connection db. Return SQLITE_OK
+** if successful or an error code if sqlite3_create_module() fails.
+*/
+int sqlite3Fts5TestRegisterTok(sqlite3 *db, fts5_api *pApi){
+  static const sqlite3_module fts5tok_module = {
+     0,                           /* iVersion      */
+     fts5tokConnectMethod,        /* xCreate       */
+     fts5tokConnectMethod,        /* xConnect      */
+     fts5tokBestIndexMethod,      /* xBestIndex    */
+     fts5tokDisconnectMethod,     /* xDisconnect   */
+     fts5tokDisconnectMethod,     /* xDestroy      */
+     fts5tokOpenMethod,           /* xOpen         */
+     fts5tokCloseMethod,          /* xClose        */
+     fts5tokFilterMethod,         /* xFilter       */
+     fts5tokNextMethod,           /* xNext         */
+     fts5tokEofMethod,            /* xEof          */
+     fts5tokColumnMethod,         /* xColumn       */
+     fts5tokRowidMethod,          /* xRowid        */
+     0,                           /* xUpdate       */
+     0,                           /* xBegin        */
+     0,                           /* xSync         */
+     0,                           /* xCommit       */
+     0,                           /* xRollback     */
+     0,                           /* xFindFunction */
+     0,                           /* xRename       */
+     0,                           /* xSavepoint    */
+     0,                           /* xRelease      */
+     0                            /* xRollbackTo   */
+  };
+  int rc;                         /* Return code */
+
+  rc = sqlite3_create_module(db, "fts5tokenize", &fts5tok_module, (void*)pApi);
+  return rc;
+}
+
+#endif /* defined(SQLITE_TEST) && defined(SQLITE_ENABLE_FTS5) */