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sqlite-parquet-vtable
mirror of https://github.com/cldellow/sqlite-parquet-vtable.git
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Very rough first cut 

supports int32, double, strings.
This commit is contained in:
Colin Dellow 2018-03-03 15:44:01 -05:00
parent f8599f8d3e
commit 1de843fca8
8 changed files with 437 additions and 572 deletions
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20
parquet/cmds.txt
View File

@ -1,3 +1,19 @@
.load ./libparquet .load ./libparquet
create virtual table parquet using parquet(filename='../csv.csv'); select 'creating without enough args';
select * from parquet; create virtual table noargs using parquet;
select 'creating with invalid file';
create virtual table nonexistent using parquet('nonexistent');
select 'creating with valid file';
create virtual table parquet using parquet('/home/cldellow/src/csv2parquet/12m.parquet.snappy');
.tables
.schema parquet
.timer on
.headers on
select count(*) from (select * from parquet limit 1);
select rowid,col0 from parquet where rowid > 5 limit 5;
select count(*) from parquet limit 1;
select sum(col0) from parquet limit 1;
select * from parquet limit 10;
select sum(length(col3)) from parquet;

13
parquet/go
View File

@ -1 +1,12 @@
./make && ../sqlite/sqlite3 -init ./cmds.txt < /dev/null #!/bin/bash
set -euo pipefail
./make
if [ ! -v DEBUG ]; then
../sqlite/sqlite3 -init ./cmds.txt < /dev/null
else
gdb -ex run --args ../sqlite/sqlite3 -init ./cmds.txt
fi

8
parquet/make
View File

@ -1,6 +1,7 @@
#!/bin/bash #!/bin/bash
set -x set -euo pipefail
#set -x
PARQUET_CPP=${PARQUET_CPP:-~/src/parquet-cpp} PARQUET_CPP=${PARQUET_CPP:-~/src/parquet-cpp}
@ -11,9 +12,10 @@ clean() {
build() { build() {
clean clean
g++ -std=c++11 -Wall -fPIC -c -g parquet.cc -I ../sqlite -lz -ldl -lpthread # -O3 -s -DNDEBUG
g++ -O3 -std=c++11 -Wall -fPIC -c -g *.cc -I ../sqlite -lz -ldl -lpthread
g++ -shared -o libparquet.so parquet.o \ g++ -O3 -shared -o libparquet.so *.o \
${PARQUET_CPP}/build/release/libparquet.a \ ${PARQUET_CPP}/build/release/libparquet.a \
${PARQUET_CPP}/thrift_ep/src/thrift_ep-install/lib/libthrift.a \ ${PARQUET_CPP}/thrift_ep/src/thrift_ep-install/lib/libthrift.a \
${PARQUET_CPP}/build/release/libarrow.so \ ${PARQUET_CPP}/build/release/libarrow.so \

670
parquet/parquet.cc
View File

@ -18,245 +18,13 @@ SQLITE_EXTENSION_INIT1
#include <ctype.h> #include <ctype.h>
#include <stdio.h> #include <stdio.h>
#include "parquet/api/reader.h" #include <memory>
char const *EMPTY_STRING = "";
void gogo() {
printf("ok");
try {
std::unique_ptr<parquet::ParquetFileReader> reader =
parquet::ParquetFileReader::OpenFile("/home/cldellow/src/csv2parquet/12m.parquet.snappy");
printf("%d\n", reader->metadata()->size());
printf("%ld\n", reader->metadata()->num_rows());
} catch (const std::exception& e) {
std::cerr << "Parquet error: " << e.what() << std::endl;
}
}
/* Max size of the error message in a CsvReader */
#define PARQUET_MXERR 200
/* Size of the CsvReader input buffer */
#define PARQUET_INBUFSZ 1024
/* A context object used when read a Parquet file. */
typedef struct CsvReader CsvReader;
struct CsvReader {
FILE *in; /* Read the Parquet text from this input stream */
char *z; /* Accumulated text for a field */
int n; /* Number of bytes in z */
int nAlloc; /* Space allocated for z[] */
int nLine; /* Current line number */
int bNotFirst; /* True if prior text has been seen */
int cTerm; /* Character that terminated the most recent field */
size_t iIn; /* Next unread character in the input buffer */
size_t nIn; /* Number of characters in the input buffer */
char *zIn; /* The input buffer */
char zErr[PARQUET_MXERR]; /* Error message */
};
/* Initialize a CsvReader object */
static void csv_reader_init(CsvReader *p){
p->in = 0;
p->z = 0;
p->n = 0;
p->nAlloc = 0;
p->nLine = 0;
p->bNotFirst = 0;
p->nIn = 0;
p->zIn = 0;
p->zErr[0] = 0;
}
/* Close and reset a CsvReader object */
static void csv_reader_reset(CsvReader *p){
if( p->in ){
fclose(p->in);
sqlite3_free(p->zIn);
}
sqlite3_free(p->z);
csv_reader_init(p);
}
/* Report an error on a CsvReader */
static void csv_errmsg(CsvReader *p, const char *zFormat, ...){
va_list ap;
va_start(ap, zFormat);
sqlite3_vsnprintf(PARQUET_MXERR, p->zErr, zFormat, ap);
va_end(ap);
}
/* Open the file associated with a CsvReader
** Return the number of errors.
*/
static int csv_reader_open(
CsvReader *p, /* The reader to open */
const char *zFilename, /* Read from this filename */
const char *zData /* ... or use this data */
){
if( zFilename ){
p->zIn = (char*)sqlite3_malloc( PARQUET_INBUFSZ );
if( p->zIn==0 ){
csv_errmsg(p, "out of memory");
return 1;
}
p->in = fopen(zFilename, "rb");
if( p->in==0 ){
csv_reader_reset(p);
csv_errmsg(p, "cannot open '%s' for reading", zFilename);
return 1;
}
}else{
assert( p->in==0 );
p->zIn = (char*)zData;
p->nIn = strlen(zData);
}
return 0;
}
/* The input buffer has overflowed. Refill the input buffer, then
** return the next character
*/
static int csv_getc_refill(CsvReader *p){
size_t got;
assert( p->iIn>=p->nIn ); /* Only called on an empty input buffer */
assert( p->in!=0 ); /* Only called if reading froma file */
got = fread(p->zIn, 1, PARQUET_INBUFSZ, p->in);
if( got==0 ) return EOF;
p->nIn = got;
p->iIn = 1;
return p->zIn[0];
}
/* Return the next character of input. Return EOF at end of input. */
static int csv_getc(CsvReader *p){
if( p->iIn >= p->nIn ){
if( p->in!=0 ) return csv_getc_refill(p);
return EOF;
}
return ((unsigned char*)p->zIn)[p->iIn++];
}
/* Increase the size of p->z and append character c to the end.
** Return 0 on success and non-zero if there is an OOM error */
static int csv_resize_and_append(CsvReader *p, char c){
char *zNew;
int nNew = p->nAlloc*2 + 100;
zNew = (char*)sqlite3_realloc64(p->z, nNew);
if( zNew ){
p->z = zNew;
p->nAlloc = nNew;
p->z[p->n++] = c;
return 0;
}else{
csv_errmsg(p, "out of memory");
return 1;
}
}
/* Append a single character to the CsvReader.z[] array.
** Return 0 on success and non-zero if there is an OOM error */
static int csv_append(CsvReader *p, char c){
if( p->n>=p->nAlloc-1 ) return csv_resize_and_append(p, c);
p->z[p->n++] = c;
return 0;
}
/* Read a single field of Parquet text. Compatible with rfc4180 and extended
** with the option of having a separator other than ",".
**
** + Input comes from p->in.
** + Store results in p->z of length p->n. Space to hold p->z comes
** from sqlite3_malloc64().
** + Keep track of the line number in p->nLine.
** + Store the character that terminates the field in p->cTerm. Store
** EOF on end-of-file.
**
** Return "" at EOF. Return 0 on an OOM error.
*/
static const char *csv_read_one_field(CsvReader *p){
int c;
p->n = 0;
c = csv_getc(p);
if( c==EOF ){
p->cTerm = EOF;
return EMPTY_STRING;
}
if( c=='"' ){
int pc, ppc;
int startLine = p->nLine;
pc = ppc = 0;
while( 1 ){
c = csv_getc(p);
if( c<='"' || pc=='"' ){
if( c=='\n' ) p->nLine++;
if( c=='"' ){
if( pc=='"' ){
pc = 0;
continue;
}
}
if( (c==',' && pc=='"')
|| (c=='\n' && pc=='"')
|| (c=='\n' && pc=='\r' && ppc=='"')
|| (c==EOF && pc=='"')
){
do{ p->n--; }while( p->z[p->n]!='"' );
p->cTerm = (char)c;
break;
}
if( pc=='"' && c!='\r' ){
csv_errmsg(p, "line %d: unescaped %c character", p->nLine, '"');
break;
}
if( c==EOF ){
csv_errmsg(p, "line %d: unterminated %c-quoted field\n",
startLine, '"');
p->cTerm = (char)c;
break;
}
}
if( csv_append(p, (char)c) ) return 0;
ppc = pc;
pc = c;
}
}else{
/* If this is the first field being parsed and it begins with the
** UTF-8 BOM (0xEF BB BF) then skip the BOM */
if( (c&0xff)==0xef && p->bNotFirst==0 ){
csv_append(p, (char)c);
c = csv_getc(p);
if( (c&0xff)==0xbb ){
csv_append(p, (char)c);
c = csv_getc(p);
if( (c&0xff)==0xbf ){
p->bNotFirst = 1;
p->n = 0;
return csv_read_one_field(p);
}
}
}
while( c>',' || (c!=EOF && c!=',' && c!='\n') ){
if( csv_append(p, (char)c) ) return 0;
c = csv_getc(p);
}
if( c=='\n' ){
p->nLine++;
if( p->n>0 && p->z[p->n-1]=='\r' ) p->n--;
}
p->cTerm = (char)c;
}
if( p->z ) p->z[p->n] = 0;
p->bNotFirst = 1;
return p->z;
}
#include "parquet_table.h"
#include "parquet_cursor.h"
/* Forward references to the various virtual table methods implemented /* Forward references to the various virtual table methods implemented
** in this file. */ * in this file. */
static int parquetCreate(sqlite3*, void*, int, const char*const*, static int parquetCreate(sqlite3*, void*, int, const char*const*,
sqlite3_vtab**,char**); sqlite3_vtab**,char**);
static int parquetConnect(sqlite3*, void*, int, const char*const*, static int parquetConnect(sqlite3*, void*, int, const char*const*,
@ -273,290 +41,65 @@ static int parquetColumn(sqlite3_vtab_cursor*,sqlite3_context*,int);
static int parquetRowid(sqlite3_vtab_cursor*,sqlite3_int64*); static int parquetRowid(sqlite3_vtab_cursor*,sqlite3_int64*);
/* An instance of the Parquet virtual table */ /* An instance of the Parquet virtual table */
typedef struct ParquetTable { typedef struct sqlite3_vtab_parquet {
sqlite3_vtab base; /* Base class. Must be first */ sqlite3_vtab base; /* Base class. Must be first */
char *zFilename; /* Name of the Parquet file */ ParquetTable* table;
char *zData; /* Raw Parquet data in lieu of zFilename */ } sqlite3_vtab_parquet;
long iStart; /* Offset to start of data in zFilename */
unsigned int nCol; /* Number of columns in the Parquet file */
unsigned int tstFlags; /* Bit values used for testing */
} ParquetTable;
/* A cursor for the Parquet virtual table */ /* A cursor for the Parquet virtual table */
typedef struct ParquetCursor { typedef struct sqlite3_vtab_cursor_parquet {
sqlite3_vtab_cursor base; /* Base class. Must be first */ sqlite3_vtab_cursor base; /* Base class. Must be first */
CsvReader rdr; /* The CsvReader object */ ParquetCursor* cursor;
char **azVal; /* Value of the current row */ } sqlite3_vtab_cursor_parquet;
int *aLen; /* Length of each entry */
sqlite3_int64 iRowid; /* The current rowid. Negative for EOF */
} ParquetCursor;
/* Transfer error message text from a reader into a ParquetTable */
static void csv_xfer_error(ParquetTable *pTab, CsvReader *pRdr){
sqlite3_free(pTab->base.zErrMsg);
pTab->base.zErrMsg = sqlite3_mprintf("%s", pRdr->zErr);
}
/* /*
** This method is the destructor fo a ParquetTable object. ** This method is the destructor fo a sqlite3_vtab_parquet object.
*/ */
static int parquetDisconnect(sqlite3_vtab *pVtab){ static int parquetDisconnect(sqlite3_vtab *pVtab){
ParquetTable *p = (ParquetTable*)pVtab; sqlite3_vtab_parquet *p = (sqlite3_vtab_parquet*)pVtab;
sqlite3_free(p->zFilename); delete p->table;
sqlite3_free(p->zData);
sqlite3_free(p); sqlite3_free(p);
return SQLITE_OK; return SQLITE_OK;
} }
/* Skip leading whitespace. Return a pointer to the first non-whitespace
** character, or to the zero terminator if the string has only whitespace */
static const char *csv_skip_whitespace(const char *z){
while( isspace((unsigned char)z[0]) ) z++;
return z;
}
/* Remove trailing whitespace from the end of string z[] */
static void csv_trim_whitespace(char *z){
size_t n = strlen(z);
while( n>0 && isspace((unsigned char)z[n]) ) n--;
z[n] = 0;
}
/* Dequote the string */
static void csv_dequote(char *z){
int j;
char cQuote = z[0];
size_t i, n;
if( cQuote!='\'' && cQuote!='"' ) return;
n = strlen(z);
if( n<2 || z[n-1]!=z[0] ) return;
for(i=1, j=0; i<n-1; i++){
if( z[i]==cQuote && z[i+1]==cQuote ) i++;
z[j++] = z[i];
}
z[j] = 0;
}
/* Check to see if the string is of the form: "TAG = VALUE" with optional
** whitespace before and around tokens. If it is, return a pointer to the
** first character of VALUE. If it is not, return NULL.
*/
static const char *csv_parameter(const char *zTag, int nTag, const char *z){
z = csv_skip_whitespace(z);
if( strncmp(zTag, z, nTag)!=0 ) return 0;
z = csv_skip_whitespace(z+nTag);
if( z[0]!='=' ) return 0;
return csv_skip_whitespace(z+1);
}
/* Decode a parameter that requires a dequoted string.
**
** Return 1 if the parameter is seen, or 0 if not. 1 is returned
** even if there is an error. If an error occurs, then an error message
** is left in p->zErr. If there are no errors, p->zErr[0]==0.
*/
static int csv_string_parameter(
CsvReader *p, /* Leave the error message here, if there is one */
const char *zParam, /* Parameter we are checking for */
const char *zArg, /* Raw text of the virtual table argment */
char **pzVal /* Write the dequoted string value here */
){
const char *zValue;
zValue = csv_parameter(zParam,(int)strlen(zParam),zArg);
if( zValue==0 ) return 0;
p->zErr[0] = 0;
if( *pzVal ){
csv_errmsg(p, "more than one '%s' parameter", zParam);
return 1;
}
*pzVal = sqlite3_mprintf("%s", zValue);
if( *pzVal==0 ){
csv_errmsg(p, "out of memory");
return 1;
}
csv_trim_whitespace(*pzVal);
csv_dequote(*pzVal);
return 1;
}
/* Return 0 if the argument is false and 1 if it is true. Return -1 if
** we cannot really tell.
*/
static int csv_boolean(const char *z){
if( sqlite3_stricmp("yes",z)==0
|| sqlite3_stricmp("on",z)==0
|| sqlite3_stricmp("true",z)==0
|| (z[0]=='1' && z[1]==0)
){
return 1;
}
if( sqlite3_stricmp("no",z)==0
|| sqlite3_stricmp("off",z)==0
|| sqlite3_stricmp("false",z)==0
|| (z[0]=='0' && z[1]==0)
){
return 0;
}
return -1;
}
/*
** Parameters:
** filename=FILENAME Name of file containing Parquet content
** data=TEXT Direct Parquet content.
** schema=SCHEMA Alternative Parquet schema.
** header=YES|NO First row of Parquet defines the names of
** columns if "yes". Default "no".
** columns=N Assume the Parquet file contains N columns.
**
**
** If schema= is omitted, then the columns are named "c0", "c1", "c2",
** and so forth. If columns=N is omitted, then the file is opened and
** the number of columns in the first row is counted to determine the
** column count. If header=YES, then the first row is skipped.
*/
static int parquetConnect( static int parquetConnect(
sqlite3 *db, sqlite3 *db,
void *pAux, void *pAux,
int argcOrig, const char *const*argv, int argc,
const char *const*argv,
sqlite3_vtab **ppVtab, sqlite3_vtab **ppVtab,
char **pzErr char **pzErr
){ ){
unsigned int argc = argcOrig; if(argc != 4 || strlen(argv[3]) < 2) {
ParquetTable *pNew = 0; /* The ParquetTable object to construct */ *pzErr = sqlite3_mprintf("must provide exactly one argument, the path to a parquet file");
int bHeader = -1; /* header= flags. -1 means not seen yet */ return SQLITE_ERROR;
int rc = SQLITE_OK; /* Result code from this routine */ }
unsigned int i, j; /* Loop counters */
int nCol = -99; /* Value of the columns= parameter */
CsvReader sRdr; /* A Parquet file reader used to store an error
** message and/or to count the number of columns */
static const char *azParam[] = {
"filename", "data", "schema",
};
char *azPValue[3]; /* Parameter values */
# define PARQUET_FILENAME (azPValue[0])
# define PARQUET_DATA (azPValue[1])
# define PARQUET_SCHEMA (azPValue[2])
// Remove the delimiting single quotes
std::string fname = argv[3];
fname = fname.substr(1, fname.length() - 2);
std::unique_ptr<ParquetTable> table(new ParquetTable(fname));
assert( sizeof(azPValue)==sizeof(azParam) ); std::unique_ptr<sqlite3_vtab_parquet, void(*)(void*)> vtab(
memset(&sRdr, 0, sizeof(sRdr)); (sqlite3_vtab_parquet*)sqlite3_malloc(sizeof(sqlite3_vtab_parquet)),
memset(azPValue, 0, sizeof(azPValue)); sqlite3_free);
for(i=3; i<argc; i++){ memset(vtab.get(), 0, sizeof(*vtab.get()));
const char *z = argv[i];
const char *zValue;
for(j=0; j<sizeof(azParam)/sizeof(azParam[0]); j++){
if( csv_string_parameter(&sRdr, azParam[j], z, &azPValue[j]) ) break;
}
if( j<sizeof(azParam)/sizeof(azParam[0]) ){
if( sRdr.zErr[0] ) goto parquet_connect_error;
}else
if( (zValue = csv_parameter("header",6,z))!=0 ){
int x;
if( bHeader>=0 ){
csv_errmsg(&sRdr, "more than one 'header' parameter");
goto parquet_connect_error;
}
x = csv_boolean(zValue);
if( x==1 ){
bHeader = 1;
}else if( x==0 ){
bHeader = 0;
}else{
csv_errmsg(&sRdr, "unrecognized argument to 'header': %s", zValue);
goto parquet_connect_error;
}
}else
if( (zValue = csv_parameter("columns",7,z))!=0 ){
if( nCol>0 ){
csv_errmsg(&sRdr, "more than one 'columns' parameter");
goto parquet_connect_error;
}
nCol = atoi(zValue);
if( nCol<=0 ){
csv_errmsg(&sRdr, "must have at least one column");
goto parquet_connect_error;
}
}else
{
csv_errmsg(&sRdr, "unrecognized parameter '%s'", z);
goto parquet_connect_error;
}
}
if( (PARQUET_FILENAME==0)==(PARQUET_DATA==0) ){
csv_errmsg(&sRdr, "must either filename= or data= but not both");
goto parquet_connect_error;
}
if( nCol<=0 && csv_reader_open(&sRdr, PARQUET_FILENAME, PARQUET_DATA) ){
goto parquet_connect_error;
}
pNew = (ParquetTable*)sqlite3_malloc( sizeof(*pNew) );
*ppVtab = (sqlite3_vtab*)pNew;
if( pNew==0 ) goto parquet_connect_oom;
memset(pNew, 0, sizeof(*pNew));
if( nCol>0 ){
pNew->nCol = nCol;
}else{
do{
const char *z = csv_read_one_field(&sRdr);
if( z==0 ) goto parquet_connect_oom;
pNew->nCol++;
}while( sRdr.cTerm==',' );
}
pNew->zFilename = PARQUET_FILENAME; PARQUET_FILENAME = 0;
pNew->zData = PARQUET_DATA; PARQUET_DATA = 0;
pNew->iStart = bHeader==1 ? ftell(sRdr.in) : 0;
csv_reader_reset(&sRdr);
if( PARQUET_SCHEMA==0 ){
const char *zSep = EMPTY_STRING;
PARQUET_SCHEMA = sqlite3_mprintf("CREATE TABLE x(");
if( PARQUET_SCHEMA==0 ) goto parquet_connect_oom;
for(i=0; i<pNew->nCol; i++){
PARQUET_SCHEMA = sqlite3_mprintf("%z%sc%d TEXT",PARQUET_SCHEMA, zSep, i);
zSep = ",";
}
PARQUET_SCHEMA = sqlite3_mprintf("%z);", PARQUET_SCHEMA);
}
rc = sqlite3_declare_vtab(db, PARQUET_SCHEMA);
if( rc ) goto parquet_connect_error;
for(i=0; i<sizeof(azPValue)/sizeof(azPValue[0]); i++){
sqlite3_free(azPValue[i]);
}
return SQLITE_OK;
parquet_connect_oom: try {
rc = SQLITE_NOMEM; std::string create = table->CreateStatement();
csv_errmsg(&sRdr, "out of memory"); int rc = sqlite3_declare_vtab(db, create.data());
if(rc)
parquet_connect_error:
if( pNew ) parquetDisconnect(&pNew->base);
for(i=0; i<sizeof(azPValue)/sizeof(azPValue[0]); i++){
sqlite3_free(azPValue[i]);
}
if( sRdr.zErr[0] ){
sqlite3_free(*pzErr);
*pzErr = sqlite3_mprintf("%s", sRdr.zErr);
}
csv_reader_reset(&sRdr);
if( rc==SQLITE_OK ) rc = SQLITE_ERROR;
return rc; return rc;
}
/* } catch (const std::exception& e) {
** Reset the current row content held by a ParquetCursor. *pzErr = sqlite3_mprintf(e.what());
*/ return SQLITE_ERROR;
static void parquetCursorRowReset(ParquetCursor *pCur){
ParquetTable *pTab = (ParquetTable*)pCur->base.pVtab;
unsigned int i;
for(i=0; i<pTab->nCol; i++){
sqlite3_free(pCur->azVal[i]);
pCur->azVal[i] = 0;
pCur->aLen[i] = 0;
} }
vtab->table = table.release();
*ppVtab = (sqlite3_vtab*)vtab.release();
return SQLITE_OK;
} }
/* /*
@ -574,96 +117,89 @@ static int parquetCreate(
} }
/* /*
** Destructor for a ParquetCursor. ** Destructor for a sqlite3_vtab_cursor_parquet.
*/ */
static int parquetClose(sqlite3_vtab_cursor *cur){ static int parquetClose(sqlite3_vtab_cursor *cur){
ParquetCursor *pCur = (ParquetCursor*)cur; sqlite3_vtab_cursor_parquet* p = (sqlite3_vtab_cursor_parquet*)cur;
parquetCursorRowReset(pCur); delete p->cursor;
csv_reader_reset(&pCur->rdr);
sqlite3_free(cur); sqlite3_free(cur);
return SQLITE_OK; return SQLITE_OK;
} }
/* /*
** Constructor for a new ParquetTable cursor object. ** Constructor for a new sqlite3_vtab_parquet cursor object.
*/ */
static int parquetOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){ static int parquetOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
ParquetTable *pTab = (ParquetTable*)p; printf("xOpen\n");
ParquetCursor *pCur;
size_t nByte; std::unique_ptr<sqlite3_vtab_cursor_parquet, void(*)(void*)> cursor(
nByte = sizeof(*pCur) + (sizeof(char*)+sizeof(int))*pTab->nCol; (sqlite3_vtab_cursor_parquet*)sqlite3_malloc(sizeof(sqlite3_vtab_cursor_parquet)),
pCur = (ParquetCursor*)sqlite3_malloc64( nByte ); sqlite3_free);
if( pCur==0 ) return SQLITE_NOMEM; memset(cursor.get(), 0, sizeof(*cursor.get()));
memset(pCur, 0, nByte);
pCur->azVal = (char**)&pCur[1]; sqlite3_vtab_parquet* pParquet = (sqlite3_vtab_parquet*)p;
pCur->aLen = (int*)&pCur->azVal[pTab->nCol]; cursor->cursor = new ParquetCursor(pParquet->table);
*ppCursor = &pCur->base;
if( csv_reader_open(&pCur->rdr, pTab->zFilename, pTab->zData) ){ *ppCursor = (sqlite3_vtab_cursor*)cursor.release();
csv_xfer_error(pTab, &pCur->rdr);
return SQLITE_ERROR;
}
return SQLITE_OK; return SQLITE_OK;
} }
/* /*
** Advance a ParquetCursor to its next row of input. ** Advance a sqlite3_vtab_cursor_parquet to its next row of input.
** Set the EOF marker if we reach the end of input. ** Set the EOF marker if we reach the end of input.
*/ */
static int parquetNext(sqlite3_vtab_cursor *cur){ static int parquetNext(sqlite3_vtab_cursor *cur){
ParquetCursor *pCur = (ParquetCursor*)cur; ParquetCursor* cursor = ((sqlite3_vtab_cursor_parquet*)cur)->cursor;
ParquetTable *pTab = (ParquetTable*)cur->pVtab; cursor->next();
unsigned int i = 0;
const char *z;
do{
z = csv_read_one_field(&pCur->rdr);
if( z==0 ){
csv_xfer_error(pTab, &pCur->rdr);
break;
}
if( i<pTab->nCol ){
if( pCur->aLen[i] < pCur->rdr.n+1 ){
char *zNew = (char*)sqlite3_realloc64(pCur->azVal[i], pCur->rdr.n+1);
if( zNew==0 ){
csv_errmsg(&pCur->rdr, "out of memory");
csv_xfer_error(pTab, &pCur->rdr);
break;
}
pCur->azVal[i] = zNew;
pCur->aLen[i] = pCur->rdr.n+1;
}
memcpy(pCur->azVal[i], z, pCur->rdr.n+1);
i++;
}
}while( pCur->rdr.cTerm==',' );
if( z==0 || (pCur->rdr.cTerm==EOF && i<pTab->nCol) ){
pCur->iRowid = -1;
}else{
pCur->iRowid++;
while( i<pTab->nCol ){
sqlite3_free(pCur->azVal[i]);
pCur->azVal[i] = 0;
pCur->aLen[i] = 0;
i++;
}
}
return SQLITE_OK; return SQLITE_OK;
} }
/* /*
** Return values of columns for the row at which the ParquetCursor ** Return values of columns for the row at which the sqlite3_vtab_cursor_parquet
** is currently pointing. ** is currently pointing.
*/ */
static int parquetColumn( static int parquetColumn(
sqlite3_vtab_cursor *cur, /* The cursor */ sqlite3_vtab_cursor *cur, /* The cursor */
sqlite3_context *ctx, /* First argument to sqlite3_result_...() */ sqlite3_context *ctx, /* First argument to sqlite3_result_...() */
int iOrig /* Which column to return */ int col /* Which column to return */
){ ){
unsigned int i = iOrig; ParquetCursor *cursor = ((sqlite3_vtab_cursor_parquet*)cur)->cursor;
ParquetCursor *pCur = (ParquetCursor*)cur; cursor->ensureColumn(col);
ParquetTable *pTab = (ParquetTable*)cur->pVtab;
if( i>=0 && i<pTab->nCol && pCur->azVal[i]!=0 ){ if(cursor->isNull(col)) {
sqlite3_result_text(ctx, pCur->azVal[i], -1, SQLITE_STATIC); sqlite3_result_null(ctx);
} else {
switch(cursor->getPhysicalType(col)) {
case parquet::Type::INT32:
{
int rv = cursor->getInt(col);
sqlite3_result_int(ctx, rv);
}
break;
case parquet::Type::DOUBLE:
{
double rv = cursor->getDouble(col);
sqlite3_result_double(ctx, rv);
}
break;
case parquet::Type::BYTE_ARRAY:
{
parquet::ByteArray* rv = cursor->getByteArray(col);
sqlite3_result_text(ctx, (const char*)rv->ptr, rv->len, SQLITE_TRANSIENT);
}
break;
case parquet::Type::BOOLEAN:
case parquet::Type::INT64:
case parquet::Type::FLOAT:
case parquet::Type::INT96:
case parquet::Type::FIXED_LEN_BYTE_ARRAY:
default:
throw std::invalid_argument("cannot handle this type");
break;
}
} }
return SQLITE_OK; return SQLITE_OK;
} }
@ -672,8 +208,8 @@ static int parquetColumn(
** Return the rowid for the current row. ** Return the rowid for the current row.
*/ */
static int parquetRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ static int parquetRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
ParquetCursor *pCur = (ParquetCursor*)cur; ParquetCursor *cursor = ((sqlite3_vtab_cursor_parquet*)cur)->cursor;
*pRowid = pCur->iRowid; *pRowid = cursor->getRowId();
return SQLITE_OK; return SQLITE_OK;
} }
@ -682,8 +218,10 @@ static int parquetRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
** row of output. ** row of output.
*/ */
static int parquetEof(sqlite3_vtab_cursor *cur){ static int parquetEof(sqlite3_vtab_cursor *cur){
ParquetCursor *pCur = (ParquetCursor*)cur; ParquetCursor* cursor = ((sqlite3_vtab_cursor_parquet*)cur)->cursor;
return pCur->iRowid<0; if(cursor->eof())
return 1;
return 0;
} }
/* /*
@ -695,8 +233,11 @@ static int parquetFilter(
int idxNum, const char *idxStr, int idxNum, const char *idxStr,
int argc, sqlite3_value **argv int argc, sqlite3_value **argv
){ ){
ParquetCursor *pCur = (ParquetCursor*)pVtabCursor; printf("xFilter\n");
ParquetTable *pTab = (ParquetTable*)pVtabCursor->pVtab; //sqlite3_vtab_cursor_parquet *pCur = (sqlite3_vtab_cursor_parquet*)pVtabCursor;
//sqlite3_vtab_parquet *pTab = (sqlite3_vtab_parquet*)pVtabCursor->pVtab;
/*
pCur->iRowid = 0; pCur->iRowid = 0;
if( pCur->rdr.in==0 ){ if( pCur->rdr.in==0 ){
assert( pCur->rdr.zIn==pTab->zData ); assert( pCur->rdr.zIn==pTab->zData );
@ -708,6 +249,7 @@ static int parquetFilter(
pCur->rdr.iIn = 0; pCur->rdr.iIn = 0;
pCur->rdr.nIn = 0; pCur->rdr.nIn = 0;
} }
*/
return parquetNext(pVtabCursor); return parquetNext(pVtabCursor);
} }

144
parquet/parquet_cursor.cc Normal file
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@ -0,0 +1,144 @@
#include "parquet_cursor.h"
ParquetCursor::ParquetCursor(ParquetTable* table) {
this->table = table;
this->rowId = -1;
// TODO: consider having a long lived handle in ParquetTable that can be borrowed
// without incurring the cost of opening the file from scratch twice
this->reader = parquet::ParquetFileReader::OpenFile(this->table->file.data());
this->rowGroupId = -1;
// TODO: handle the case where rowgroups have disjoint schemas?
// TODO: or at least, fail fast if detected
this->rowsLeftInRowGroup = 0;
this->numRows = reader->metadata()->num_rows();
this->numRowGroups = reader->metadata()->num_row_groups();
}
void ParquetCursor::nextRowGroup() {
// TODO: skip row groups that cannot satisfy the constraints
if(this->rowGroupId >= this->numRowGroups)
return;
rowGroupId++;
rowGroupMetadata = this->reader->metadata()->RowGroup(0);
rowsLeftInRowGroup = rowGroupMetadata->num_rows();
rowGroup = reader->RowGroup(rowGroupId);
for(unsigned int i = 0; i < scanners.size(); i++)
scanners[i] = NULL;
while(types.size() < (unsigned int)rowGroupMetadata->num_columns()) {
types.push_back(rowGroupMetadata->schema()->Column(0)->physical_type());
}
for(unsigned int i = 0; i < (unsigned int)rowGroupMetadata->num_columns(); i++) {
types[i] = rowGroupMetadata->schema()->Column(i)->physical_type();
}
}
void ParquetCursor::next() {
if(rowsLeftInRowGroup == 0)
nextRowGroup();
rowsLeftInRowGroup--;
rowId++;
}
int ParquetCursor::getRowId() {
return rowId;
}
bool ParquetCursor::eof() {
return rowId >= numRows;
}
void ParquetCursor::ensureColumn(int col) {
// need to ensure a scanner exists (and skip the # of rows in the rowgroup)
while((unsigned int)col >= scanners.size()) {
scanners.push_back(std::shared_ptr<parquet::Scanner>());
colRows.push_back(-1);
colNulls.push_back(false);
colIntValues.push_back(0);
colDoubleValues.push_back(0);
colByteArrayValues.push_back(parquet::ByteArray());
}
if(scanners[col].get() == NULL) {
std::shared_ptr<parquet::ColumnReader> colReader = rowGroup->Column(col);
scanners[col] = parquet::Scanner::Make(colReader);
// TODO: potentially skip rows if rowsLeftInRowGroup != rowGroupMetadata->num_rows()
}
// Actually fetch a value, stash data in colRows, colNulls, colValues
if(colRows[col] != rowId) {
colRows[col] = rowId;
bool wasNull = false;
switch(types[col]) {
case parquet::Type::INT32:
{
parquet::Int32Scanner* s = (parquet::Int32Scanner*)scanners[col].get();
int rv = 0;
if(s->NextValue(&rv, &wasNull)) {
colIntValues[col] = rv;
} else {
throw std::invalid_argument("unexpectedly lacking a next value");
}
}
break;
case parquet::Type::DOUBLE:
{
parquet::DoubleScanner* s = (parquet::DoubleScanner*)scanners[col].get();
double rv = 0;
if(s->NextValue(&rv, &wasNull)) {
colDoubleValues[col] = rv;
} else {
throw std::invalid_argument("unexpectedly lacking a next value");
}
}
break;
case parquet::Type::BYTE_ARRAY:
{
parquet::ByteArrayScanner* s = (parquet::ByteArrayScanner*)scanners[col].get();
if(!s->NextValue(&colByteArrayValues[col], &wasNull)) {
throw std::invalid_argument("unexpectedly lacking a next value");
}
}
break;
case parquet::Type::BOOLEAN:
case parquet::Type::INT64:
case parquet::Type::FLOAT:
case parquet::Type::INT96:
case parquet::Type::FIXED_LEN_BYTE_ARRAY:
default:
throw std::invalid_argument("cannot handle");
break;
}
colNulls[col] = wasNull;
}
}
bool ParquetCursor::isNull(int col) {
return colNulls[col];
}
int ParquetCursor::getInt(int col) {
return colIntValues[col];
}
double ParquetCursor::getDouble(int col) {
return colDoubleValues[col];
}
parquet::ByteArray* ParquetCursor::getByteArray(int col) {
return &colByteArrayValues[col];
}
parquet::Type::type ParquetCursor::getPhysicalType(int col) {
// return rowGroupMetadata->schema()->Column(col)->physical_type();
return types[col];
}

52
parquet/parquet_cursor.h Normal file
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@ -0,0 +1,52 @@
#ifndef PARQUET_CURSOR_H
#define PARQUET_CURSOR_H
#include "parquet_table.h"
#include "parquet/api/reader.h"
class ParquetCursor {
ParquetTable* table;
std::unique_ptr<parquet::ParquetFileReader> reader;
std::unique_ptr<parquet::RowGroupMetaData> rowGroupMetadata;
std::shared_ptr<parquet::RowGroupReader> rowGroup;
std::vector<std::shared_ptr<parquet::Scanner>> scanners;
std::vector<parquet::Type::type> types;
std::vector<int> colRows;
std::vector<bool> colNulls;
std::vector<uintptr_t> colIntValues;
std::vector<double> colDoubleValues;
std::vector<parquet::ByteArray> colByteArrayValues;
int rowId;
int rowGroupId;
int numRows;
int numRowGroups;
int rowsLeftInRowGroup;
void nextRowGroup();
public:
ParquetCursor(ParquetTable* table);
int getRowId();
void next();
bool eof();
void ensureColumn(int col);
bool isNull(int col);
int getInt(int col);
double getDouble(int col);
parquet::ByteArray* getByteArray(int col);
parquet::Type::type getPhysicalType(int col);
/*
sqlite3_result_double()
sqlite3_result_int()
sqlite3_result_int64()
sqlite3_result_null()
sqlite3_result_text()
*/
};
#endif

84
parquet/parquet_table.cc Normal file
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@ -0,0 +1,84 @@
#include "parquet_table.h"
#include "parquet/api/reader.h"
ParquetTable::ParquetTable(std::string file) {
this->file = file;
}
std::string ParquetTable::CreateStatement() {
std::unique_ptr<parquet::ParquetFileReader> reader = parquet::ParquetFileReader::OpenFile(file.data());
// TODO: parse columns from file
std::string text("CREATE TABLE x(");
auto schema = reader->metadata()->schema();
printf("num cols: %d\n", schema->num_columns());
for(auto i = 0; i < schema->num_columns(); i++) {
auto _col = schema->GetColumnRoot(i);
if(!_col->is_primitive()) {
throw std::invalid_argument("parquet file has non-primitive column");
}
if(_col->is_repeated()) {
throw std::invalid_argument("parquet file has non-scalar column");
}
parquet::schema::PrimitiveNode* col = (parquet::schema::PrimitiveNode*)_col;
printf("col %d[p=%d:%s, l=%d:%s] is %s\n",
i,
col->physical_type(),
parquet::TypeToString(col->physical_type()).data(),
col->logical_type(),
parquet::LogicalTypeToString(col->logical_type()).data(),
col->name().data());
if(i > 0)
text += ", ";
text += col->name();
std::string type;
switch(col->physical_type()) {
case parquet::Type::BOOLEAN:
type = "TINYINT";
break;
case parquet::Type::INT32:
if(col->logical_type() == parquet::LogicalType::NONE) {
type = "INT";
} else if(col->logical_type() == parquet::LogicalType::INT_8) {
type = "TINYINT";
} else if(col->logical_type() == parquet::LogicalType::INT_16) {
type = "SMALLINT";
}
break;
case parquet::Type::INT64:
type = "BIGINT";
break;
case parquet::Type::FLOAT:
type = "REAL";
break;
case parquet::Type::DOUBLE:
type = "DOUBLE";
break;
case parquet::Type::BYTE_ARRAY:
if(col->logical_type() == parquet::LogicalType::UTF8) {
type = "TEXT";
}
break;
case parquet::Type::FIXED_LEN_BYTE_ARRAY:
case parquet::Type::INT96:
default:
break;
}
if(type.empty()) {
throw std::invalid_argument("unsupported type");
}
printf("...%s\n", type.data());
text += " ";
text += type;
}
text +=");";
return text;
}

14
parquet/parquet_table.h Normal file
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@ -0,0 +1,14 @@
#ifndef PARQUET_TABLE_H
#define PARQUET_TABLE_H
#include <string>
class ParquetTable {
public:
ParquetTable(std::string file);
std::string CreateStatement();
std::string file;
};
#endif