Clarify some namings in keyring code

It's not clear to someone new to the code that "key provider" in these
files refers to what's called "key provider type" elsewhere.

Rename these to make it easier for the next person.

Author: Anders Åstrand

contrib/pg_tde/src/include/keyring/keyring_api.h

@@ -87,7 +87,7 @@ typedef struct KmipKeyring
 	char	   *kmip_cert_path;
 } KmipKeyring;
 
-extern void RegisterKeyProvider(const TDEKeyringRoutine *routine, ProviderType type);
+extern void RegisterKeyProviderType(const TDEKeyringRoutine *routine, ProviderType type);
 
 extern KeyInfo *KeyringGetKey(GenericKeyring *keyring, const char *key_name, KeyringReturnCodes *returnCode);
 extern KeyInfo *KeyringGenerateNewKeyAndStore(GenericKeyring *keyring, const char *key_name, unsigned key_len);

contrib/pg_tde/src/keyring/keyring_api.c

@@ -11,31 +11,31 @@
 #include <assert.h>
 #include <openssl/rand.h>
 
-typedef struct KeyProviders
+typedef struct RegisteredKeyProviderType
 {
 	TDEKeyringRoutine *routine;
 	ProviderType type;
-} KeyProviders;
+} RegisteredKeyProviderType;
 
 #ifndef FRONTEND
-static List *registeredKeyProviders = NIL;
+static List *registeredKeyProviderTypes = NIL;
 #else
-static SimplePtrList registeredKeyProviders = {NULL, NULL};
+static SimplePtrList registeredKeyProviderTypes = {NULL, NULL};
 #endif
 
-static KeyProviders *find_key_provider(ProviderType type);
+static RegisteredKeyProviderType *find_key_provider_type(ProviderType type);
 static void KeyringStoreKey(GenericKeyring *keyring, KeyInfo *key);
 static KeyInfo *KeyringGenerateNewKey(const char *key_name, unsigned key_len);
 
 #ifndef FRONTEND
-static KeyProviders *
-find_key_provider(ProviderType type)
+static RegisteredKeyProviderType *
+find_key_provider_type(ProviderType type)
 {
 	ListCell   *lc;
 
-	foreach(lc, registeredKeyProviders)
+	foreach(lc, registeredKeyProviderTypes)
 	{
-		KeyProviders *kp = (KeyProviders *) lfirst(lc);
+		RegisteredKeyProviderType *kp = (RegisteredKeyProviderType *) lfirst(lc);
 
 		if (kp->type == type)
 		{
@@ -45,14 +45,14 @@ find_key_provider(ProviderType type)
 	return NULL;
 }
 #else
-static KeyProviders *
-find_key_provider(ProviderType type)
+static RegisteredKeyProviderType *
+find_key_provider_type(ProviderType type)
 {
 	SimplePtrListCell *lc;
 
-	for (lc = registeredKeyProviders.head; lc; lc = lc->next)
+	for (lc = registeredKeyProviderTypes.head; lc; lc = lc->next)
 	{
-		KeyProviders *kp = (KeyProviders *) lc->ptr;
+		RegisteredKeyProviderType *kp = (RegisteredKeyProviderType *) lc->ptr;
 
 		if (kp->type == type)
 		{
@@ -64,9 +64,9 @@ find_key_provider(ProviderType type)
 #endif							/* !FRONTEND */
 
 void
-RegisterKeyProvider(const TDEKeyringRoutine *routine, ProviderType type)
+RegisterKeyProviderType(const TDEKeyringRoutine *routine, ProviderType type)
 {
-	KeyProviders *kp;
+	RegisteredKeyProviderType *kp;
 #ifndef FRONTEND
 	MemoryContext oldcontext;
 #endif
@@ -75,29 +75,29 @@ RegisterKeyProvider(const TDEKeyringRoutine *routine, ProviderType type)
 	Assert(routine->keyring_get_key != NULL);
 	Assert(routine->keyring_store_key != NULL);
 
-	kp = find_key_provider(type);
+	kp = find_key_provider_type(type);
 	if (kp)
 		ereport(ERROR,
 				(errmsg("Key provider of type %d already registered", type)));
 
 #ifndef FRONTEND
 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
 #endif
-	kp = palloc_object(KeyProviders);
+	kp = palloc_object(RegisteredKeyProviderType);
 	kp->routine = (TDEKeyringRoutine *) routine;
 	kp->type = type;
 #ifndef FRONTEND
-	registeredKeyProviders = lappend(registeredKeyProviders, kp);
+	registeredKeyProviderTypes = lappend(registeredKeyProviderTypes, kp);
 	MemoryContextSwitchTo(oldcontext);
 #else
-	simple_ptr_list_append(&registeredKeyProviders, kp);
+	simple_ptr_list_append(&registeredKeyProviderTypes, kp);
 #endif
 }
 
 KeyInfo *
 KeyringGetKey(GenericKeyring *keyring, const char *key_name, KeyringReturnCodes *returnCode)
 {
-	KeyProviders *kp = find_key_provider(keyring->type);
+	RegisteredKeyProviderType *kp = find_key_provider_type(keyring->type);
 
 	if (kp == NULL)
 	{
@@ -112,7 +112,7 @@ KeyringGetKey(GenericKeyring *keyring, const char *key_name, KeyringReturnCodes
 static void
 KeyringStoreKey(GenericKeyring *keyring, KeyInfo *key)
 {
-	KeyProviders *kp = find_key_provider(keyring->type);
+	RegisteredKeyProviderType *kp = find_key_provider_type(keyring->type);
 
 	if (kp == NULL)
 		ereport(ERROR,

contrib/pg_tde/src/keyring/keyring_file.c

@@ -37,7 +37,7 @@ const TDEKeyringRoutine keyringFileRoutine = {
 void
 InstallFileKeyring(void)
 {
-	RegisterKeyProvider(&keyringFileRoutine, FILE_KEY_PROVIDER);
+	RegisterKeyProviderType(&keyringFileRoutine, FILE_KEY_PROVIDER);
 }
 
 static KeyInfo *

contrib/pg_tde/src/keyring/keyring_kmip.c

@@ -35,7 +35,7 @@ const TDEKeyringRoutine keyringKmipRoutine = {
 void
 InstallKmipKeyring(void)
 {
-	RegisterKeyProvider(&keyringKmipRoutine, KMIP_KEY_PROVIDER);
+	RegisterKeyProviderType(&keyringKmipRoutine, KMIP_KEY_PROVIDER);
 }
 
 typedef struct KmipCtx

contrib/pg_tde/src/keyring/keyring_vault.c

@@ -79,7 +79,7 @@ const TDEKeyringRoutine keyringVaultV2Routine = {
 void
 InstallVaultV2Keyring(void)
 {
-	RegisterKeyProvider(&keyringVaultV2Routine, VAULT_V2_KEY_PROVIDER);
+	RegisterKeyProviderType(&keyringVaultV2Routine, VAULT_V2_KEY_PROVIDER);
 }
 
 static bool