PROTOCOLS

EditTransaction

Defined in fuchsia.pkg.rewrite/rewrite.fidl

A unit of editing for rewrite rules.

Add

Adds a rewrite rule with highest priority. If rule already exists, this API will prioritize it over other rules.

• request rule the rewrite rule to persist.

• error a zx_status value indicating failure. One of the following:
  • ZX_ERR_INVALID_ARGS if url is not a valid fuchsia-pkg:// URL. See fuchsia-pkg URL.

fuchsia-pkg URL: https://fuchsia.dev/fuchsia-src/concepts/storage/package_url

Request

Name	Type
rule	Rule

Response

Name	Type
result	EditTransaction_Add_Result

Commit

Commits this transaction, or detect another transaction that committed before this one.

• error a zx_status value indicating failure. One of the following:
  • ZX_ERR_UNAVAILABLE if another transaction committed before this one.
  • ZX_ERR_ACCESS_DENIED if editing dynamic rewrite rules is permanently disabled.

Request

Name	Type

Response

Name	Type
result	EditTransaction_Commit_Result

ListDynamic

Returns an iterator over all dynamic (editable) rewrite rules. The iterator will reflect any changes made to the rewrite rules so far in this transaction.

• request iterator a request for an iterator.

Request

Name	Type
iterator	request<RuleIterator>

ResetAll

Removes all dynamically configured rewrite rules, leaving only any statically configured rules.

Request

Name	Type

Engine

Defined in fuchsia.pkg.rewrite/rewrite.fidl

This manages fuchsia-pkg:// rewrite rules.

When a package resolver is asked to resolve a fuchsia-pkg URL, it must first iterate through its sequence of rewrite rules (given by List). The rewrite engine will rewrite the given URL with the first rule that:

• matches the given URL
• produces a valid URL when applied to the given URL

If no rules match, the URL is resolved as-is.

This is intended to be implemented by package resolver components, and used by repository administration tools.

List

Returns an iterator over all rewrite rules.

• request iterator a request for an iterator.

Request

Name	Type
iterator	request<RuleIterator>

ListStatic

Returns an iterator over all static (immutable) rewrite rules. These rules are handled as lower priority than dynamic rules and cannot be modified (although they can be overridden) by EditTransactions.

• request iterator a request for an iterator.

Request

Name	Type
iterator	request<RuleIterator>

StartEditTransaction

Begins a rule edit transaction.

• request transaction a request for an EditTransaction.

Request

Name	Type
transaction	request<EditTransaction>

TestApply

Rewrites the given url with the current rewrite rule set, returning the rewritten url. If no rules match or a rule matches but performs an identity transformation, this API returns url unchanged.

This API is intended only for reflecting on rule side effects. Using this API to pre-apply the rules, then passing the result to fuchsia.pkg/PackageResolver.Resolve would apply the rules twice.

• request url the url to rewrite.

• response rewritten the rewritten url.

• error a zx_status value indicating failure. One of the following:
  • ZX_ERR_INVALID_ARGS if url is not a valid fuchsia-pkg:// URL. See fuchsia-pkg URL.

fuchsia-pkg URL: https://fuchsia.dev/fuchsia-src/concepts/storage/package_url

Request

Name	Type
url	string

Response

Name	Type
result	Engine_TestApply_Result

RuleIterator

Defined in fuchsia.pkg.rewrite/rewrite.fidl

The iterator over all the rewrite rules defined in a Engine.

Next

Advances the iterator and returns the next batch of rules.

• response rules a vector of Rule rules. Will return an empty vector and then close the channel when there are no more rules.

Request

Name	Type

Response

Name	Type
rules	vector<Rule>

STRUCTS

EditTransaction_Add_Response

Defined in fuchsia.pkg.rewrite/rewrite.fidl

Name	Type	Description	Default

EditTransaction_Commit_Response

Defined in fuchsia.pkg.rewrite/rewrite.fidl

Name	Type	Description	Default

Engine_TestApply_Response

Defined in fuchsia.pkg.rewrite/rewrite.fidl

Name	Type	Description	Default
rewritten	string		No default

LiteralRule

Defined in fuchsia.pkg.rewrite/rewrite.fidl

A literal match and replacement rule.

Examples

Replaces example.com with test.example.com for all packages

{
    host_match: "example.com"
    host_replacement: "test.example.com"
    path_prefix_match: "/"
    path_prefix_replacement: "/"
}

Replaces example.com with test.example.com for fuchsia-pkg://example.com/rolldice. A package called "rolldice" in another repo would not be rewritten.

{
    host_match: "example.com"
    host_replacement: "test.example.com"
    path_prefix_match: "/rolldice"
    path_prefix_replacement: "/rolldice"
}

Name	Type	Description	Default
host_match	string	The exact hostname to match.	No default
host_replacement	string	The new hostname to replace the matched host_match with.	No default
path_prefix_match	string	The absolute path to a package or directory to match against. If path_prefix_match ends with '/', it will match any packages or subdirectories below the matched path. If path_prefix_match does not end with '/', it will be interpreted as as an exact match. Examples "/example" only matches a package called "example" at the root of the repo. "/parent/examples" and "/examples" would not match. "/example/" would match any package under the "example" path at the root of the repo. For example, "/example/", "/example/package" would both match.	No default
path_prefix_replacement	string	The absolute path to a single package or a directory to replace the matched path_prefix_match with. path_prefix_match and path_prefix_replacement must both match directories or both match exact packages. Mixing the two forms is not allowed.	No default

UNIONS

EditTransaction_Add_Result strict

Defined in fuchsia.pkg.rewrite/rewrite.fidl

Name	Type	Description
response	EditTransaction_Add_Response
err	zx/status

EditTransaction_Commit_Result strict

Defined in fuchsia.pkg.rewrite/rewrite.fidl

Name	Type	Description
response	EditTransaction_Commit_Response
err	zx/status

Engine_TestApply_Result strict

Defined in fuchsia.pkg.rewrite/rewrite.fidl

Name	Type	Description
response	Engine_TestApply_Response
err	zx/status

Rule flexible

Defined in fuchsia.pkg.rewrite/rewrite.fidl

A rewrite rule, represented as an xunion for future compatibility.

Name	Type	Description
literal	LiteralRule