From 52120a99579f2dd730138529fd0f1111dbdf1eb9 Mon Sep 17 00:00:00 2001
From: Art Cancro <ajc@citadel.org>
Date: Mon, 21 Aug 2023 10:09:45 -0900
Subject: [PATCH] bdb_decompress_if_necessary() now operates on DBT instead of
 cdbdata

This allows us to maintain the DB_DBT_REALLOC heuristics.
---
 .../server/backends/berkeley_db/berkeley_db.c | 31 +++++++++----------
 citadel/server/server.h                       |  1 -
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/citadel/server/backends/berkeley_db/berkeley_db.c b/citadel/server/backends/berkeley_db/berkeley_db.c
index 529d4c60a..60063099e 100644
--- a/citadel/server/backends/berkeley_db/berkeley_db.c
+++ b/citadel/server/backends/berkeley_db/berkeley_db.c
@@ -327,12 +327,11 @@ void bdb_close_databases(void) {
 }
 
 
-// Decompress a database item if it was compressed on disk
-void bdb_decompress_if_necessary(struct cdbdata *cdb) {
+// Decompress a DBT data block if it was compressed on disk.
+void bdb_decompress_if_necessary(DBT *d) {
 	static int magic = COMPRESS_MAGIC;
 
-	if ((cdb == NULL) || (cdb->ptr == NULL) || (cdb->len < sizeof(magic)) || (memcmp(cdb->ptr, &magic, sizeof(magic)))) {
-		cdb->cdbfree_must_free_ptr = 0;
+	if ((d == NULL) || (d->data == NULL) || (d->size < sizeof(magic)) || (memcmp(d->data, &magic, sizeof(magic)))) {
 		return;
 	}
 
@@ -346,12 +345,12 @@ void bdb_decompress_if_necessary(struct cdbdata *cdb) {
 
 	memset(&zheader, 0, sizeof(struct CtdlCompressHeader));
 	cplen = sizeof(struct CtdlCompressHeader);
-	if (sizeof(struct CtdlCompressHeader) > cdb->len) {
-		cplen = cdb->len;
+	if (sizeof(struct CtdlCompressHeader) > d->size) {
+		cplen = d->size;
 	}
-	memcpy(&zheader, cdb->ptr, cplen);
+	memcpy(&zheader, d->data, cplen);
 
-	compressed_data = cdb->ptr;
+	compressed_data = d->data;
 	compressed_data += sizeof(struct CtdlCompressHeader);
 
 	sourceLen = (uLongf) zheader.compressed_len;
@@ -364,10 +363,9 @@ void bdb_decompress_if_necessary(struct cdbdata *cdb) {
 		bdb_abort();
 	}
 
-	//free(cdb->ptr);
-	cdb->len = (size_t) destLen;
-	cdb->ptr = uncompressed_data;
-	cdb->cdbfree_must_free_ptr = 1;
+	free(d->data);
+	d->size = (size_t) destLen;
+	d->data = uncompressed_data;
 }
 
 
@@ -562,6 +560,8 @@ struct cdbdata *bdb_fetch(int cdb, const void *key, int keylen) {
 		return NULL;
 	}
 
+	bdb_decompress_if_necessary(&TSD->dbdata[cdb]);
+
 	tempcdb = (struct cdbdata *) malloc(sizeof(struct cdbdata));
 	if (tempcdb == NULL) {
 		syslog(LOG_ERR, "bdb: bdb_fetch() cannot allocate memory for tempcdb: %m");
@@ -570,7 +570,6 @@ struct cdbdata *bdb_fetch(int cdb, const void *key, int keylen) {
 	else {
 		tempcdb->len = TSD->dbdata[cdb].size;
 		tempcdb->ptr = TSD->dbdata[cdb].data;
-		bdb_decompress_if_necessary(tempcdb);
 		return (tempcdb);
 	}
 }
@@ -578,9 +577,6 @@ struct cdbdata *bdb_fetch(int cdb, const void *key, int keylen) {
 
 // Free a cdbdata item.
 void bdb_free(struct cdbdata *cdb) {
-	if (cdb->cdbfree_must_free_ptr) {
-		free(cdb->ptr);
-	}
 	free(cdb);
 }
 
@@ -635,10 +631,11 @@ struct cdbdata *bdb_next_item(int cdb) {
 		return NULL;	// presumably, we are at the end
 	}
 
+	bdb_decompress_if_necessary(&TSD->dbdata[cdb]);
+
 	cdbret = (struct cdbdata *) malloc(sizeof(struct cdbdata));
 	cdbret->len = TSD->dbdata[cdb].size;
 	cdbret->ptr = TSD->dbdata[cdb].data;
-	bdb_decompress_if_necessary(cdbret);
 
 	return (cdbret);
 }
diff --git a/citadel/server/server.h b/citadel/server/server.h
index b16289bf6..c628df2a1 100644
--- a/citadel/server/server.h
+++ b/citadel/server/server.h
@@ -70,7 +70,6 @@ struct ExpressMessage {
 struct cdbdata {
 	size_t len;			// size of datum pointed to by ptr
 	char *ptr;			// datum
-	int cdbfree_must_free_ptr;	// nonzero if cdb_free() is expected to free(ptr)
 };
 
 
-- 
2.39.2