t allows a wrapped_tree to be manipulated as a tree of chunked_byte_vector

key was too long, or contained invalid steps.

Invalid index for a subkey

A value was not found in the durable store.

A tree does not exists under key in the durable store.

Attempted to write/read to/from a value at offset, beyond the limit.

Durable_storage.t was empty.

Cannot modify a readonly value.

Cannot read from or write to more than 2,048 bytes

encoding is a Tezos_tree_encoding for t.

• raises Durable_empty

key is the type that indexes t. It enforces several constraints:

• a key's length is bounded.
• a key is a series of non-empty steps, where
• a step is preceded by '/'
• a step only contains alphanumeric ascii, or dots ('.')

max_key_length is the maximum length of a key in bytes.

• raises Invalid_key

find_value durable key optionally looks for the value encoded at key in durable.

• raises Value_not_found

copy_tree_exn tree ?edit_readonly from_key to_key produces a new tree in which a copy of the entire subtree at from_key is copied to to_key.

~edit_readonly:true allows a tree to be copied into a readonly location.

• raises Readonly_value

move_tree_exn tree from_key to_key produces a new tree in which the entire subtree at from_key is moved to to_key.

• raises Readonly_value

list durable key returns the subkeys under key.

count_subtrees durable key returns the number of subtrees under key.

subtree_name_at durable key n returns the name of the n_th subtree under key.

delete ?edit_readonly durable key deletes the value at and/or subtrees of key.

• raises Readonly_value

  when edit_readonly is not set while trying to edit the readonly section.

hash durable key retrieves the tree hash of the value at the given key. This is not the same as the hash of the value.

hash_exn durable key retrieves the tree hash of the value at the given key. This is not the same as the hash of the value.

• raises Value_not_found

  when key is not found

set_value_exn durable key str installs the value str in durable under key, replacing any previous contents under this key without fetching it.

write_value_exn durable ?edit_readonly key offset bytes writes bytes to key, starting at the given offset.

If no value at key exists, it is created.

~edit_readonly:true allows a value to be written into a readonly location.

• raises Out_of_bounds

• raises Readonly_value

  iff edit_readonly is not set to true when attempting to write in the readonly section.

read_value_exn durable key offset max_bytes reads up to max_bytes bytes from the value at key, starting at the given offset.

• raises Value_not_found

  when key is not found.

• raises Out_of_bounds

  when offset is larger than the value.