From 4d1c1143c2a149187f806f8a261847520cc50733 Mon Sep 17 00:00:00 2001 From: Jakob Borg Date: Tue, 12 Jan 2016 12:01:07 +0100 Subject: [PATCH] Retract hash algo proposal for the moment --- specs/bep-v1.rst | 12 ++--------- users/hashalgo.rst | 53 ---------------------------------------------- 2 files changed, 2 insertions(+), 63 deletions(-) delete mode 100644 users/hashalgo.rst diff --git a/specs/bep-v1.rst b/specs/bep-v1.rst index eaf6e438f..0a2b040fd 100644 --- a/specs/bep-v1.rst +++ b/specs/bep-v1.rst @@ -337,7 +337,7 @@ folder Flags field contains the following single bit flags: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Reserved | Hash |D|P|R| + | Reserved |D|P|R| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ :Bit 31 ("R", Read Only): @@ -351,14 +351,6 @@ folder Flags field contains the following single bit flags: :Bit 29 ("D", Ignore Deletes): is set for folders that the device will ignore deletes for. -:Bits 25-28 (Hash): - indicates the hash algorithm in use for this folder, as a four bit integer. - The value values are: - - - 0: SHA256 - - 1: Murmur3-128 - - 2-15: Reserved for future usage - The **Options** field contains a list of options that apply to the folder. Fields (Device Structure) @@ -912,7 +904,7 @@ directions. Read Only ~~~~~~~~~ -In read only mode, a device does not apply any updates from the cluster, +In read only mode, a device does not apply any updates from the cluster, but publishes changes of its local folder to the cluster as usual. The local folder can be seen as a "master copy" that is never affected by the actions of other cluster devices. diff --git a/users/hashalgo.rst b/users/hashalgo.rst deleted file mode 100644 index 358b13ed9..000000000 --- a/users/hashalgo.rst +++ /dev/null @@ -1,53 +0,0 @@ -.. _hashalgo: - -Hash Algorithms -=============== - -.. versionadded:: 0.13.0 - -Description ------------ - -A folder can use one of several available hash algorithms when determining -changes to files. The algorithms have different properties -- see the table -below where the differences between the algorithms are highlighted. - -========= ======== ============= ================= ================ -Algorithm Speed Delta Changes Efficient Renames Efficient Copies -========= ======== ============= ================= ================ -SHA256 Slow Yes Yes **Yes** -Murmur3 **Fast** Yes Yes No -========= ======== ============= ================= ================ - -Speed: - This affects the speed with which content can be hashed. A "slow" - algorithm requires a lot of CPU power, while a "fast" algorithm does not. - The actual scanning speed may however be limited by the disk's transfer - rate. - -Delta Changes: - Indicates whether changes to the contents of a file are transferred - efficiently. "Yes" means that only the changed blocks are transferred, - "no" means the whole file must be resent. - -Efficient Renames: - Indicates whether renaming a file on one device results in a renaming - operation on another device ("yes"), or whether the renamed file must be - transferred over the network ("no"). - -Efficient Copies: - Indicates whether a copy of a file on one device results in a local copy - operation on another device ("yes"), or whether the copy must be - transferred over the network ("no"). - -Changing the Folder Hash Algorithm ----------------------------------- - -The hash algorithm can only be set when a folder is added to the -configuration, it can not be changed afterwards. To change the hash algorithm -of a folder it must be removed and then added again with the new hash -algorithm. This necessarily results in a full (slow) rescan of the folder -contents. - -The hash algorithm for a given folder must be the same for all devices sharing -that folder.