[PATCH v3 08/11] odb/transaction: add transaction env interface

@@ -27,6 +27,7 @@
 #include "path.h"
 #include "read-cache-ll.h"
 #include "setup.h"
+#include "strvec.h"
 #include "tempfile.h"
 #include "tmp-objdir.h"
 

@@ -1687,6 +1688,18 @@ static int odb_transaction_files_commit(struct odb_transaction *base)
 	return 0;
 }
 
+static int odb_transaction_files_env(struct odb_transaction *base,
+				     struct strvec *env)
+{
+	struct odb_transaction_files *transaction =
+		container_of(base, struct odb_transaction_files, base);
+
+	odb_transaction_files_prepare(&transaction->base);
+	strvec_pushv(env, tmp_objdir_env(transaction->objdir));
+
+	return 0;
+}
+
 int odb_transaction_files_begin(struct odb_source *source,
 				struct odb_transaction **out)
 {

@@ -1696,6 +1709,7 @@ int odb_transaction_files_begin(struct odb_source *source,
 	transaction->base.source = source;
 	transaction->base.commit = odb_transaction_files_commit;
 	transaction->base.write_object_stream = odb_transaction_files_write_object_stream;
+	transaction->base.env = odb_transaction_files_env;
 	*out = &transaction->base;
 
 	return 0;

@@ -42,3 +42,11 @@ int odb_transaction_write_object_stream(struct odb_transaction *transaction,
 {
 	return transaction->write_object_stream(transaction, stream, len, oid);
 }
+
+int odb_transaction_env(struct odb_transaction *transaction, struct strvec *env)
+{
+	if (!transaction)
+		return 0;
+
+	return transaction->env(transaction, env);
+}

@@ -34,6 +34,14 @@ struct odb_transaction {
 	int (*write_object_stream)(struct odb_transaction *transaction,
 				   struct odb_write_stream *stream, size_t len,
 				   struct object_id *oid);
+
+	/*
+	 * This callback is expected to populate the provided strvec with the
+	 * environment variables that a child process should inherit so that its
+	 * object writes participate in the transaction. Returns 0 on success, a
+	 * negative error code otherwise.
+	 */
+	int (*env)(struct odb_transaction *transaction, struct strvec *env);
 };
 
 /*

@@ -69,4 +77,13 @@ int odb_transaction_write_object_stream(struct odb_transaction *transaction,
 					struct odb_write_stream *stream,
 					size_t len, struct object_id *oid);
 
+/*
+ * Populates the provided strvec with the environment variables that a child
+ * process should inherit so that its object writes participate in the
+ * transaction, suitable for using via child_process.env. Returns 0 on success,
+ * a negative error code otherwise. Note that, if the specified transaction is
+ * NULL, the function is a no-op and no error is returned.
+ */
+int odb_transaction_env(struct odb_transaction *transaction, struct strvec *env);
+
 #endif