diff options
Diffstat (limited to 'ext/misc/fileio.c')
| -rw-r--r-- | ext/misc/fileio.c | 682 |
1 files changed, 651 insertions, 31 deletions
diff --git a/ext/misc/fileio.c b/ext/misc/fileio.c index 2c00ad971..7dbac4043 100644 --- a/ext/misc/fileio.c +++ b/ext/misc/fileio.c @@ -11,30 +11,95 @@ ****************************************************************************** ** ** This SQLite extension implements SQL functions readfile() and -** writefile(). +** writefile(), and eponymous virtual type "fsdir". +** +** WRITEFILE(FILE, DATA [, MODE [, MTIME]]): +** +** If neither of the optional arguments is present, then this UDF +** function writes blob DATA to file FILE. If successful, the number +** of bytes written is returned. If an error occurs, NULL is returned. +** +** If the first option argument - MODE - is present, then it must +** be passed an integer value that corresponds to a POSIX mode +** value (file type + permissions, as returned in the stat.st_mode +** field by the stat() system call). Three types of files may +** be written/created: +** +** regular files: (mode & 0170000)==0100000 +** symbolic links: (mode & 0170000)==0120000 +** directories: (mode & 0170000)==0040000 +** +** For a directory, the DATA is ignored. For a symbolic link, it is +** interpreted as text and used as the target of the link. For a +** regular file, it is interpreted as a blob and written into the +** named file. Regardless of the type of file, its permissions are +** set to (mode & 0777) before returning. +** +** If the optional MTIME argument is present, then it is interpreted +** as an integer - the number of seconds since the unix epoch. The +** modification-time of the target file is set to this value before +** returning. +** +** If three or more arguments are passed to this function and an +** error is encountered, an exception is raised. +** +** READFILE(FILE): +** +** Read and return the contents of file FILE (type blob) from disk. +** +** FSDIR: +** +** Used as follows: +** +** SELECT * FROM fsdir($path [, $dir]); +** +** Parameter $path is an absolute or relative pathname. If the file that it +** refers to does not exist, it is an error. If the path refers to a regular +** file or symbolic link, it returns a single row. Or, if the path refers +** to a directory, it returns one row for the directory, and one row for each +** file within the hierarchy rooted at $path. +** +** Each row has the following columns: +** +** name: Path to file or directory (text value). +** mode: Value of stat.st_mode for directory entry (an integer). +** mtime: Value of stat.st_mtime for directory entry (an integer). +** data: For a regular file, a blob containing the file data. For a +** symlink, a text value containing the text of the link. For a +** directory, NULL. +** +** If a non-NULL value is specified for the optional $dir parameter and +** $path is a relative path, then $path is interpreted relative to $dir. +** And the paths returned in the "name" column of the table are also +** relative to directory $dir. */ #include "sqlite3ext.h" SQLITE_EXTENSION_INIT1 #include <stdio.h> +#include <string.h> +#include <assert.h> + +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <dirent.h> +#include <time.h> +#include <utime.h> +#include <errno.h> + + +#define FSDIR_SCHEMA "(name,mode,mtime,data,path HIDDEN,dir HIDDEN)" /* -** Implementation of the "readfile(X)" SQL function. The entire content -** of the file named X is read and returned as a BLOB. NULL is returned -** if the file does not exist or is unreadable. +** Set the result stored by context ctx to a blob containing the +** contents of file zName. */ -static void readfileFunc( - sqlite3_context *context, - int argc, - sqlite3_value **argv -){ - const char *zName; +static void readFileContents(sqlite3_context *ctx, const char *zName){ FILE *in; long nIn; void *pBuf; - (void)(argc); /* Unused parameter */ - zName = (const char*)sqlite3_value_text(argv[0]); - if( zName==0 ) return; in = fopen(zName, "rb"); if( in==0 ) return; fseek(in, 0, SEEK_END); @@ -42,7 +107,7 @@ static void readfileFunc( rewind(in); pBuf = sqlite3_malloc( nIn ); if( pBuf && 1==fread(pBuf, nIn, 1, in) ){ - sqlite3_result_blob(context, pBuf, nIn, sqlite3_free); + sqlite3_result_blob(ctx, pBuf, nIn, sqlite3_free); }else{ sqlite3_free(pBuf); } @@ -50,36 +115,588 @@ static void readfileFunc( } /* -** Implementation of the "writefile(X,Y)" SQL function. The argument Y -** is written into file X. The number of bytes written is returned. Or -** NULL is returned if something goes wrong, such as being unable to open -** file X for writing. +** Implementation of the "readfile(X)" SQL function. The entire content +** of the file named X is read and returned as a BLOB. NULL is returned +** if the file does not exist or is unreadable. +*/ +static void readfileFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + const char *zName; + (void)(argc); /* Unused parameter */ + zName = (const char*)sqlite3_value_text(argv[0]); + if( zName==0 ) return; + readFileContents(context, zName); +} + +/* +** Set the error message contained in context ctx to the results of +** vprintf(zFmt, ...). +*/ +static void ctxErrorMsg(sqlite3_context *ctx, const char *zFmt, ...){ + char *zMsg = 0; + va_list ap; + va_start(ap, zFmt); + zMsg = sqlite3_vmprintf(zFmt, ap); + sqlite3_result_error(ctx, zMsg, -1); + sqlite3_free(zMsg); + va_end(ap); +} + +/* +** Argument zFile is the name of a file that will be created and/or written +** by SQL function writefile(). This function ensures that the directory +** zFile will be written to exists, creating it if required. The permissions +** for any path components created by this function are set to (mode&0777). +** +** If an OOM condition is encountered, SQLITE_NOMEM is returned. Otherwise, +** SQLITE_OK is returned if the directory is successfully created, or +** SQLITE_ERROR otherwise. +*/ +static int makeDirectory( + const char *zFile, + mode_t mode +){ + char *zCopy = sqlite3_mprintf("%s", zFile); + int rc = SQLITE_OK; + + if( zCopy==0 ){ + rc = SQLITE_NOMEM; + }else{ + int nCopy = strlen(zCopy); + int i = 1; + + while( rc==SQLITE_OK ){ + struct stat sStat; + int rc; + + for(; zCopy[i]!='/' && i<nCopy; i++); + if( i==nCopy ) break; + zCopy[i] = '\0'; + + rc = stat(zCopy, &sStat); + if( rc!=0 ){ + if( mkdir(zCopy, mode & 0777) ) rc = SQLITE_ERROR; + }else{ + if( !S_ISDIR(sStat.st_mode) ) rc = SQLITE_ERROR; + } + zCopy[i] = '/'; + i++; + } + + sqlite3_free(zCopy); + } + + return rc; +} + +/* +** This function does the work for the writefile() UDF. Refer to +** header comments at the top of this file for details. +*/ +static int writeFile( + sqlite3_context *pCtx, /* Context to return bytes written in */ + const char *zFile, /* File to write */ + sqlite3_value *pData, /* Data to write */ + mode_t mode, /* MODE parameter passed to writefile() */ + sqlite3_int64 mtime /* MTIME parameter (or -1 to not set time) */ +){ + if( S_ISLNK(mode) ){ + const char *zTo = (const char*)sqlite3_value_text(pData); + if( symlink(zTo, zFile)<0 ) return 1; + }else{ + if( S_ISDIR(mode) ){ + if( mkdir(zFile, mode) ){ + /* The mkdir() call to create the directory failed. This might not + ** be an error though - if there is already a directory at the same + ** path and either the permissions already match or can be changed + ** to do so using chmod(), it is not an error. */ + struct stat sStat; + if( errno!=EEXIST + || 0!=stat(zFile, &sStat) + || !S_ISDIR(sStat.st_mode) + || ((sStat.st_mode&0777)!=(mode&0777) && 0!=chmod(zFile, mode&0777)) + ){ + return 1; + } + } + }else{ + sqlite3_int64 nWrite = 0; + const char *z; + int rc = 0; + FILE *out = fopen(zFile, "wb"); + if( out==0 ) return 1; + z = (const char*)sqlite3_value_blob(pData); + if( z ){ + sqlite3_int64 n = fwrite(z, 1, sqlite3_value_bytes(pData), out); + nWrite = sqlite3_value_bytes(pData); + if( nWrite!=n ){ + rc = 1; + } + } + fclose(out); + if( rc==0 && mode && chmod(zFile, mode & 0777) ){ + rc = 1; + } + if( rc ) return 2; + sqlite3_result_int64(pCtx, nWrite); + } + } + + if( mtime>=0 ){ + struct timespec times[2]; + times[0].tv_nsec = times[1].tv_nsec = 0; + times[0].tv_sec = time(0); + times[1].tv_sec = mtime; + if( utimensat(AT_FDCWD, zFile, times, AT_SYMLINK_NOFOLLOW) ){ + return 1; + } + } + + return 0; +} + +/* +** Implementation of the "writefile(W,X[,Y[,Z]]])" SQL function. +** Refer to header comments at the top of this file for details. */ static void writefileFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ - FILE *out; - const char *z; - sqlite3_int64 rc; const char *zFile; + mode_t mode = 0; + int res; + sqlite3_int64 mtime = -1; + + if( argc<2 || argc>4 ){ + sqlite3_result_error(context, + "wrong number of arguments to function writefile()", -1 + ); + return; + } - (void)(argc); /* Unused parameter */ zFile = (const char*)sqlite3_value_text(argv[0]); if( zFile==0 ) return; - out = fopen(zFile, "wb"); - if( out==0 ) return; - z = (const char*)sqlite3_value_blob(argv[1]); - if( z==0 ){ - rc = 0; + if( argc>=3 ){ + mode = sqlite3_value_int(argv[2]); + } + if( argc==4 ){ + mtime = sqlite3_value_int64(argv[3]); + } + + res = writeFile(context, zFile, argv[1], mode, mtime); + if( res==1 && errno==ENOENT ){ + if( makeDirectory(zFile, mode)==SQLITE_OK ){ + res = writeFile(context, zFile, argv[1], mode, mtime); + } + } + + if( argc>2 && res!=0 ){ + if( S_ISLNK(mode) ){ + ctxErrorMsg(context, "failed to create symlink: %s", zFile); + }else if( S_ISDIR(mode) ){ + ctxErrorMsg(context, "failed to create directory: %s", zFile); + }else{ + ctxErrorMsg(context, "failed to write file: %s", zFile); + } + } +} + +#ifndef SQLITE_OMIT_VIRTUALTABLE + +/* +** Cursor type for recursively iterating through a directory structure. +*/ +typedef struct fsdir_cursor fsdir_cursor; +typedef struct FsdirLevel FsdirLevel; + +struct FsdirLevel { + DIR *pDir; /* From opendir() */ + char *zDir; /* Name of directory (nul-terminated) */ +}; + +struct fsdir_cursor { + sqlite3_vtab_cursor base; /* Base class - must be first */ + + int nLvl; /* Number of entries in aLvl[] array */ + int iLvl; /* Index of current entry */ + FsdirLevel *aLvl; /* Hierarchy of directories being traversed */ + + const char *zBase; + int nBase; + + struct stat sStat; /* Current lstat() results */ + char *zPath; /* Path to current entry */ + sqlite3_int64 iRowid; /* Current rowid */ +}; + +typedef struct fsdir_tab fsdir_tab; +struct fsdir_tab { + sqlite3_vtab base; /* Base class - must be first */ +}; + +/* +** Construct a new fsdir virtual table object. +*/ +static int fsdirConnect( + sqlite3 *db, + void *pAux, + int argc, const char *const*argv, + sqlite3_vtab **ppVtab, + char **pzErr +){ + fsdir_tab *pNew = 0; + int rc; + + rc = sqlite3_declare_vtab(db, "CREATE TABLE x" FSDIR_SCHEMA); + if( rc==SQLITE_OK ){ + pNew = (fsdir_tab*)sqlite3_malloc( sizeof(*pNew) ); + if( pNew==0 ) return SQLITE_NOMEM; + memset(pNew, 0, sizeof(*pNew)); + } + *ppVtab = (sqlite3_vtab*)pNew; + return rc; +} + +/* +** This method is the destructor for fsdir vtab objects. +*/ +static int fsdirDisconnect(sqlite3_vtab *pVtab){ + sqlite3_free(pVtab); + return SQLITE_OK; +} + +/* +** Constructor for a new fsdir_cursor object. +*/ +static int fsdirOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){ + fsdir_cursor *pCur; + pCur = sqlite3_malloc( sizeof(*pCur) ); + if( pCur==0 ) return SQLITE_NOMEM; + memset(pCur, 0, sizeof(*pCur)); + pCur->iLvl = -1; + *ppCursor = &pCur->base; + return SQLITE_OK; +} + +/* +** Reset a cursor back to the state it was in when first returned +** by fsdirOpen(). +*/ +static void fsdirResetCursor(fsdir_cursor *pCur){ + int i; + for(i=0; i<=pCur->iLvl; i++){ + FsdirLevel *pLvl = &pCur->aLvl[i]; + if( pLvl->pDir ) closedir(pLvl->pDir); + sqlite3_free(pLvl->zDir); + } + sqlite3_free(pCur->zPath); + pCur->aLvl = 0; + pCur->zPath = 0; + pCur->zBase = 0; + pCur->nBase = 0; + pCur->iLvl = -1; + pCur->iRowid = 1; +} + +/* +** Destructor for an fsdir_cursor. +*/ +static int fsdirClose(sqlite3_vtab_cursor *cur){ + fsdir_cursor *pCur = (fsdir_cursor*)cur; + + fsdirResetCursor(pCur); + sqlite3_free(pCur->aLvl); + sqlite3_free(pCur); + return SQLITE_OK; +} + +/* +** Set the error message for the virtual table associated with cursor +** pCur to the results of vprintf(zFmt, ...). +*/ +static void fsdirSetErrmsg(fsdir_cursor *pCur, const char *zFmt, ...){ + va_list ap; + va_start(ap, zFmt); + pCur->base.pVtab->zErrMsg = sqlite3_vmprintf(zFmt, ap); + va_end(ap); +} + + +/* +** Advance an fsdir_cursor to its next row of output. +*/ +static int fsdirNext(sqlite3_vtab_cursor *cur){ + fsdir_cursor *pCur = (fsdir_cursor*)cur; + mode_t m = pCur->sStat.st_mode; + + pCur->iRowid++; + if( S_ISDIR(m) ){ + /* Descend into this directory */ + int iNew = pCur->iLvl + 1; + FsdirLevel *pLvl; + if( iNew>=pCur->nLvl ){ + int nNew = iNew+1; + int nByte = nNew*sizeof(FsdirLevel); + FsdirLevel *aNew = (FsdirLevel*)sqlite3_realloc(pCur->aLvl, nByte); + if( aNew==0 ) return SQLITE_NOMEM; + memset(&aNew[pCur->nLvl], 0, sizeof(FsdirLevel)*(nNew-pCur->nLvl)); + pCur->aLvl = aNew; + pCur->nLvl = nNew; + } + pCur->iLvl = iNew; + pLvl = &pCur->aLvl[iNew]; + + pLvl->zDir = pCur->zPath; + pCur->zPath = 0; + pLvl->pDir = opendir(pLvl->zDir); + if( pLvl->pDir==0 ){ + fsdirSetErrmsg(pCur, "cannot read directory: %s", pCur->zPath); + return SQLITE_ERROR; + } + } + + while( pCur->iLvl>=0 ){ + FsdirLevel *pLvl = &pCur->aLvl[pCur->iLvl]; + struct dirent *pEntry = readdir(pLvl->pDir); + if( pEntry ){ + if( pEntry->d_name[0]=='.' ){ + if( pEntry->d_name[1]=='.' && pEntry->d_name[2]=='\0' ) continue; + if( pEntry->d_name[1]=='\0' ) continue; + } + sqlite3_free(pCur->zPath); + pCur->zPath = sqlite3_mprintf("%s/%s", pLvl->zDir, pEntry->d_name); + if( pCur->zPath==0 ) return SQLITE_NOMEM; + if( lstat(pCur->zPath, &pCur->sStat) ){ + fsdirSetErrmsg(pCur, "cannot stat file: %s", pCur->zPath); + return SQLITE_ERROR; + } + return SQLITE_OK; + } + closedir(pLvl->pDir); + sqlite3_free(pLvl->zDir); + pLvl->pDir = 0; + pLvl->zDir = 0; + pCur->iLvl--; + } + + /* EOF */ + sqlite3_free(pCur->zPath); + pCur->zPath = 0; + return SQLITE_OK; +} + +/* +** Return values of columns for the row at which the series_cursor +** is currently pointing. +*/ +static int fsdirColumn( + sqlite3_vtab_cursor *cur, /* The cursor */ + sqlite3_context *ctx, /* First argument to sqlite3_result_...() */ + int i /* Which column to return */ +){ + fsdir_cursor *pCur = (fsdir_cursor*)cur; + switch( i ){ + case 0: { /* name */ + sqlite3_result_text(ctx, &pCur->zPath[pCur->nBase], -1, SQLITE_TRANSIENT); + break; + } + + case 1: /* mode */ + sqlite3_result_int64(ctx, pCur->sStat.st_mode); + break; + + case 2: /* mtime */ + sqlite3_result_int64(ctx, pCur->sStat.st_mtime); + break; + + case 3: { /* data */ + mode_t m = pCur->sStat.st_mode; + if( S_ISDIR(m) ){ + sqlite3_result_null(ctx); + }else if( S_ISLNK(m) ){ + char aStatic[64]; + char *aBuf = aStatic; + int nBuf = 64; + int n; + + while( 1 ){ + n = readlink(pCur->zPath, aBuf, nBuf); + if( n<nBuf ) break; + if( aBuf!=aStatic ) sqlite3_free(aBuf); + nBuf = nBuf*2; + aBuf = sqlite3_malloc(nBuf); + if( aBuf==0 ){ + sqlite3_result_error_nomem(ctx); + return SQLITE_NOMEM; + } + } + + sqlite3_result_text(ctx, aBuf, n, SQLITE_TRANSIENT); + if( aBuf!=aStatic ) sqlite3_free(aBuf); + }else{ + readFileContents(ctx, pCur->zPath); + } + } + } + return SQLITE_OK; +} + +/* +** Return the rowid for the current row. In this implementation, the +** first row returned is assigned rowid value 1, and each subsequent +** row a value 1 more than that of the previous. +*/ +static int fsdirRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ + fsdir_cursor *pCur = (fsdir_cursor*)cur; + *pRowid = pCur->iRowid; + return SQLITE_OK; +} + +/* +** Return TRUE if the cursor has been moved off of the last +** row of output. +*/ +static int fsdirEof(sqlite3_vtab_cursor *cur){ + fsdir_cursor *pCur = (fsdir_cursor*)cur; + return (pCur->zPath==0); +} + +/* +** xFilter callback. +*/ +static int fsdirFilter( + sqlite3_vtab_cursor *cur, + int idxNum, const char *idxStr, + int argc, sqlite3_value **argv +){ + const char *zDir = 0; + fsdir_cursor *pCur = (fsdir_cursor*)cur; + + fsdirResetCursor(pCur); + + if( idxNum==0 ){ + fsdirSetErrmsg(pCur, "table function fsdir requires an argument"); + return SQLITE_ERROR; + } + + assert( argc==idxNum && (argc==1 || argc==2) ); + zDir = (const char*)sqlite3_value_text(argv[0]); + if( zDir==0 ){ + fsdirSetErrmsg(pCur, "table function fsdir requires a non-NULL argument"); + return SQLITE_ERROR; + } + if( argc==2 ){ + pCur->zBase = (const char*)sqlite3_value_text(argv[1]); + } + if( pCur->zBase ){ + pCur->nBase = strlen(pCur->zBase)+1; + pCur->zPath = sqlite3_mprintf("%s/%s", pCur->zBase, zDir); + }else{ + pCur->zPath = sqlite3_mprintf("%s", zDir); + } + + if( pCur->zPath==0 ){ + return SQLITE_NOMEM; + } + if( lstat(pCur->zPath, &pCur->sStat) ){ + fsdirSetErrmsg(pCur, "cannot stat file: %s", pCur->zPath); + return SQLITE_ERROR; + } + + return SQLITE_OK; +} + +/* +** SQLite will invoke this method one or more times while planning a query +** that uses the generate_series virtual table. This routine needs to create +** a query plan for each invocation and compute an estimated cost for that +** plan. +** +** In this implementation idxNum is used to represent the +** query plan. idxStr is unused. +** +** The query plan is represented by bits in idxNum: +** +** (1) start = $value -- constraint exists +** (2) stop = $value -- constraint exists +** (4) step = $value -- constraint exists +** (8) output in descending order +*/ +static int fsdirBestIndex( + sqlite3_vtab *tab, + sqlite3_index_info *pIdxInfo +){ + int i; /* Loop over constraints */ + int idx4 = -1; + int idx5 = -1; + + const struct sqlite3_index_constraint *pConstraint; + pConstraint = pIdxInfo->aConstraint; + for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){ + if( pConstraint->usable==0 ) continue; + if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue; + if( pConstraint->iColumn==4 ) idx4 = i; + if( pConstraint->iColumn==5 ) idx5 = i; + } + + if( idx4<0 ){ + pIdxInfo->idxNum = 0; + pIdxInfo->estimatedCost = (double)(((sqlite3_int64)1) << 50); }else{ - rc = fwrite(z, 1, sqlite3_value_bytes(argv[1]), out); + pIdxInfo->aConstraintUsage[idx4].omit = 1; + pIdxInfo->aConstraintUsage[idx4].argvIndex = 1; + if( idx5>=0 ){ + pIdxInfo->aConstraintUsage[idx5].omit = 1; + pIdxInfo->aConstraintUsage[idx5].argvIndex = 2; + pIdxInfo->idxNum = 2; + pIdxInfo->estimatedCost = 10.0; + }else{ + pIdxInfo->idxNum = 1; + pIdxInfo->estimatedCost = 100.0; + } } - fclose(out); - sqlite3_result_int64(context, rc); + + return SQLITE_OK; } +/* +** Register the "fsdir" virtual table. +*/ +static int fsdirRegister(sqlite3 *db){ + static sqlite3_module fsdirModule = { + 0, /* iVersion */ + 0, /* xCreate */ + fsdirConnect, /* xConnect */ + fsdirBestIndex, /* xBestIndex */ + fsdirDisconnect, /* xDisconnect */ + 0, /* xDestroy */ + fsdirOpen, /* xOpen - open a cursor */ + fsdirClose, /* xClose - close a cursor */ + fsdirFilter, /* xFilter - configure scan constraints */ + fsdirNext, /* xNext - advance a cursor */ + fsdirEof, /* xEof - check for end of scan */ + fsdirColumn, /* xColumn - read data */ + fsdirRowid, /* xRowid - read data */ + 0, /* xUpdate */ + 0, /* xBegin */ + 0, /* xSync */ + 0, /* xCommit */ + 0, /* xRollback */ + 0, /* xFindMethod */ + 0, /* xRename */ + }; + + int rc = sqlite3_create_module(db, "fsdir", &fsdirModule, 0); + return rc; +} +#else /* SQLITE_OMIT_VIRTUALTABLE */ +# define fsdirRegister(x) SQLITE_OK +#endif #ifdef _WIN32 __declspec(dllexport) @@ -95,8 +712,11 @@ int sqlite3_fileio_init( rc = sqlite3_create_function(db, "readfile", 1, SQLITE_UTF8, 0, readfileFunc, 0, 0); if( rc==SQLITE_OK ){ - rc = sqlite3_create_function(db, "writefile", 2, SQLITE_UTF8, 0, + rc = sqlite3_create_function(db, "writefile", -1, SQLITE_UTF8, 0, writefileFunc, 0, 0); } + if( rc==SQLITE_OK ){ + rc = fsdirRegister(db); + } return rc; } |