I think I am incorrectly using the API, which may be leading to my
segmentation fault...
I have a variable amount (22k -> 1MB) of data, split across several
blobs to insert into a database. I transactify the process to save
some time (alot by my tests).
sqlite3_exec(db, "BEGIN IMMEDIATE", NULL, NULL, NULL);
-For each blob...
sqlite3_prepare(db, "INSERT INTO table1 (blobData) VALUES (?1)", -1,
&stmt, NULL);
sqlite3_bind_blob(stmt, 1, blobData, blobSize, SQLITE_TRANSIENT);
sqlite3_step(stmt); // with appropriate error checking
sqlite3_finalize(stmt);
-end for each.
sqlite3_exec(db, "COMMIT", NULL, NULL, NULL);
Is this incorrect? What I feel may be incorrect is the fact that I am
finalizing the stmt before the commit. I programmed this way because
I did not want to have a separate stmt for each INSERT. But I was
wondering if the finalize is destroying copy of the blob data sqlite
made during the call to sqlite3_bind_blob().
--
Rich Rattanni
On 7/1/07, Rich Rattanni <[EMAIL PROTECTED]> wrote:
I stand corrected, thank you Andrew. I seriuosly doubt it is a bug in
SQlite, but I have had a hell of a time with sqlite and binding
dynamically allocated text and binary data.
On 7/1/07, Andrew Finkenstadt <[EMAIL PROTECTED]> wrote:
> On 7/1/07, Rich Rattanni <[EMAIL PROTECTED]> wrote:
> >
> > I was trying to look through the SQLITE source code to see how the
> > sqlite3_bind_blob routine worked.
> >
> > sqlite3_bind_blob passes the data pointer to bindText
> > bindText passes the data pointer to sqlite3VdbeMemSetStr
> > sqlite3VdbeMemSetStr then does...
> > ...
> > pMem->z = (char *)z;
> > if( xDel==SQLITE_STATIC ){
> > pMem->flags = MEM_Static;
> > }else if( xDel==SQLITE_TRANSIENT ){
> > pMem->flags = MEM_Ephem;
> > }else{
> > pMem->flags = MEM_Dyn;
> > pMem->xDel = xDel;
> > }
> > ...
> >
> > I dont see anywhere where sqlite3 copies data to a private buffer, I
> > just see where sqlite3 saves a copy of the user pointer.
> >
>
>
> Further down in that function, after setting MEM_Ephem, there are these
> lines of code:
>
> if( pMem->flags&MEM_Ephem ){
> return sqlite3VdbeMemMakeWriteable(pMem);
> }
>
> which does the memory copy when SQLITE_TRANSIENT is used as a side-effect of
> making it "writable".
>
> In your original outline you issued sqlite3_step before freeing the memory.
> If you leave it that way, you can get away with SQLITE_STATIC when binding
> the blob... which might indicate something by whether/where the crash still
> occurs.
>
> --andy
> just a sqlite user, not really a knower-of-code
>
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