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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997-2002
* Sleepycat Software. All rights reserved.
*
* $Id: java_locked.h,v 1.1.1.1 2003/11/20 22:13:34 toshok Exp $
*/
#ifndef _JAVA_LOCKED_H_
#define _JAVA_LOCKED_H_
/*
* Used as argument to locked_dbt_get().
*/
typedef enum _OpKind {
inOp, /* setting data in database (passing data in) */
outOp, /* getting data from database to user memory */
inOutOp /* both getting/setting data */
} OpKind;
/*
* LOCKED_DBT
*
* A stack variable LOCKED_DBT should be declared for each Dbt used in a
* native call to the DB API. Before the DBT can be used, locked_dbt_get()
* must be called to temporarily convert any java array found in the
* Dbt (which has a pointer to a DBT_JAVAINFO struct) to actual bytes
* in memory that remain locked in place. These bytes are used during
* the call to the DB C API, and are released and/or copied back when
* locked_dbt_put is called.
*/
typedef struct _locked_dbt
{
/* these are accessed externally to locked_dbt_ functions */
DBT_JAVAINFO *javainfo;
unsigned int java_array_len;
jobject jdbt;
/* these are for used internally by locked_dbt_ functions */
jbyte *java_data;
jbyte *before_data;
OpKind kind;
#define LOCKED_ERROR 0x01 /* error occurred */
#define LOCKED_CREATE_DATA 0x02 /* must create data on the fly */
#define LOCKED_REALLOC_NONNULL 0x04 /* DB_DBT_REALLOC flag, nonnull data */
u_int32_t flags;
} LOCKED_DBT;
/* Fill the LOCKED_DBT struct and lock the Java byte array */
extern int locked_dbt_get(LOCKED_DBT *, JNIEnv *, DB_ENV *, jobject, OpKind);
/* unlock the Java byte array */
extern void locked_dbt_put(LOCKED_DBT *, JNIEnv *, DB_ENV *);
/* realloc the Java byte array */
extern int locked_dbt_realloc(LOCKED_DBT *, JNIEnv *, DB_ENV *);
/*
* LOCKED_STRING
*
* A LOCKED_STRING exists temporarily to convert a java jstring object
* to a char *. Because the memory for the char * string is
* managed by the JVM, it must be released when we are done
* looking at it. Typically, locked_string_get() is called at the
* beginning of a function for each jstring object, and locked_string_put
* is called at the end of each function for each LOCKED_STRING.
*/
typedef struct _locked_string
{
/* this accessed externally to locked_string_ functions */
const char *string;
/* this is used internally by locked_string_ functions */
jstring jstr;
} LOCKED_STRING;
extern int locked_string_get(LOCKED_STRING *, JNIEnv *jnienv, jstring jstr);
extern void locked_string_put(LOCKED_STRING *, JNIEnv *jnienv); /* this unlocks and frees mem */
#endif /* !_JAVA_LOCKED_H_ */
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