aconfig: create flag.map storage file

    Ok(modified_parsed_flags)

}

fn assign_flag_ids<'a, I>(package: &str, parsed_flags_iter: I) -> Result<HashMap<String, u32>>

pub fn assign_flag_ids<'a, I>(package: &str, parsed_flags_iter: I) -> Result<HashMap<String, u32>>

where

    I: Iterator<Item = &'a ProtoParsedFlag> + Clone,

{

/*

 * Copyright (C) 2024 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

use crate::commands::assign_flag_ids;

use crate::storage::{self, FlagPackage};

use anyhow::{anyhow, Result};

#[derive(PartialEq, Debug)]

pub struct FlagTableHeader {

    pub version: u32,

    pub container: String,

    pub file_size: u32,

    pub num_flags: u32,

    pub bucket_offset: u32,

    pub node_offset: u32,

}

impl FlagTableHeader {

    fn new(container: &str, num_flags: u32) -> Self {

        Self {

            version: storage::FILE_VERSION,

            container: String::from(container),

            file_size: 0,

            num_flags,

            bucket_offset: 0,

            node_offset: 0,

        }

    }

    fn as_bytes(&self) -> Vec<u8> {

        let mut result = Vec::new();

        result.extend_from_slice(&self.version.to_le_bytes());

        let container_bytes = self.container.as_bytes();

        result.extend_from_slice(&(container_bytes.len() as u32).to_le_bytes());

        result.extend_from_slice(container_bytes);

        result.extend_from_slice(&self.file_size.to_le_bytes());

        result.extend_from_slice(&self.num_flags.to_le_bytes());

        result.extend_from_slice(&self.bucket_offset.to_le_bytes());

        result.extend_from_slice(&self.node_offset.to_le_bytes());

        result

    }

}

#[derive(PartialEq, Debug, Clone)]

pub struct FlagTableNode {

    pub package_id: u32,

    pub flag_name: String,

    pub flag_id: u32,

    pub next_offset: Option<u32>,

    pub bucket_index: u32,

}

impl FlagTableNode {

    fn new(package_id: u32, flag_name: &str, flag_id: u32, num_buckets: u32) -> Self {

        let full_flag_name = package_id.to_string() + "/" + flag_name;

        let bucket_index = storage::get_bucket_index(&full_flag_name, num_buckets);

        Self {

            package_id,

            flag_name: flag_name.to_string(),

            flag_id,

            next_offset: None,

            bucket_index,

        }

    }

    fn as_bytes(&self) -> Vec<u8> {

        let mut result = Vec::new();

        result.extend_from_slice(&self.package_id.to_le_bytes());

        let name_bytes = self.flag_name.as_bytes();

        result.extend_from_slice(&(name_bytes.len() as u32).to_le_bytes());

        result.extend_from_slice(name_bytes);

        result.extend_from_slice(&self.flag_id.to_le_bytes());

        result.extend_from_slice(&self.next_offset.unwrap_or(0).to_le_bytes());

        result

    }

}

#[derive(PartialEq, Debug)]

pub struct FlagTable {

    pub header: FlagTableHeader,

    pub buckets: Vec<Option<u32>>,

    pub nodes: Vec<FlagTableNode>,

}

impl FlagTable {

    fn create_nodes(package: &FlagPackage, num_buckets: u32) -> Result<Vec<FlagTableNode>> {

        let flag_names = package.boolean_flags.iter().map(|pf| pf.name()).collect::<Vec<_>>();

        println!("{:?}", flag_names);

        let flag_ids =

            assign_flag_ids(package.package_name, package.boolean_flags.iter().copied())?;

        package

            .boolean_flags

            .iter()

            .map(|&pf| {

                let fid = flag_ids

                    .get(pf.name())

                    .ok_or(anyhow!(format!("missing flag id for {}", pf.name())))?;

                Ok(FlagTableNode::new(package.package_id, pf.name(), *fid, num_buckets))

            })

            .collect::<Result<Vec<_>>>()

    }

    pub fn new(container: &str, packages: &[FlagPackage]) -> Result<Self> {

        // create table

        let num_flags = packages.iter().map(|pkg| pkg.boolean_flags.len() as u32).sum();

        let num_buckets = storage::get_table_size(num_flags)?;

        let mut table = Self {

            header: FlagTableHeader::new(container, num_flags),

            buckets: vec![None; num_buckets as usize],

            nodes: packages

                .iter()

                .map(|pkg| FlagTable::create_nodes(pkg, num_buckets))

                .collect::<Result<Vec<_>>>()?

                .concat(),

        };

        // initialize all header fields

        table.header.bucket_offset = table.header.as_bytes().len() as u32;

        table.header.node_offset = table.header.bucket_offset + num_buckets * 4;

        table.header.file_size = table.header.node_offset

            + table.nodes.iter().map(|x| x.as_bytes().len()).sum::<usize>() as u32;

        // sort nodes by bucket index for efficiency

        table.nodes.sort_by(|a, b| a.bucket_index.cmp(&b.bucket_index));

        // fill all node offset

        let mut offset = table.header.node_offset;

        for i in 0..table.nodes.len() {

            let node_bucket_idx = table.nodes[i].bucket_index;

            let next_node_bucket_idx = if i + 1 < table.nodes.len() {

                Some(table.nodes[i + 1].bucket_index)

            } else {

                None

            };

            if table.buckets[node_bucket_idx as usize].is_none() {

                table.buckets[node_bucket_idx as usize] = Some(offset);

            }

            offset += table.nodes[i].as_bytes().len() as u32;

            if let Some(index) = next_node_bucket_idx {

                if index == node_bucket_idx {

                    table.nodes[i].next_offset = Some(offset);

                }

            }

        }

        Ok(table)

    }

    pub fn as_bytes(&self) -> Vec<u8> {

        [

            self.header.as_bytes(),

            self.buckets.iter().map(|v| v.unwrap_or(0).to_le_bytes()).collect::<Vec<_>>().concat(),

            self.nodes.iter().map(|v| v.as_bytes()).collect::<Vec<_>>().concat(),

        ]

        .concat()

    }

}

#[cfg(test)]

mod tests {

    use super::*;

    use crate::storage::{

        group_flags_by_package, tests::parse_all_test_flags, tests::read_str_from_bytes,

        tests::read_u32_from_bytes,

    };

    impl FlagTableHeader {

        // test only method to deserialize back into the header struct

        fn from_bytes(bytes: &[u8]) -> Result<Self> {

            let mut head = 0;

            Ok(Self {

                version: read_u32_from_bytes(bytes, &mut head)?,

                container: read_str_from_bytes(bytes, &mut head)?,

                file_size: read_u32_from_bytes(bytes, &mut head)?,

                num_flags: read_u32_from_bytes(bytes, &mut head)?,

                bucket_offset: read_u32_from_bytes(bytes, &mut head)?,

                node_offset: read_u32_from_bytes(bytes, &mut head)?,

            })

        }

    }

    impl FlagTableNode {

        // test only method to deserialize back into the node struct

        fn from_bytes(bytes: &[u8], num_buckets: u32) -> Result<Self> {

            let mut head = 0;

            let mut node = Self {

                package_id: read_u32_from_bytes(bytes, &mut head)?,

                flag_name: read_str_from_bytes(bytes, &mut head)?,

                flag_id: read_u32_from_bytes(bytes, &mut head)?,

                next_offset: match read_u32_from_bytes(bytes, &mut head)? {

                    0 => None,

                    val => Some(val),

                },

                bucket_index: 0,

            };

            let full_flag_name = node.package_id.to_string() + "/" + &node.flag_name;

            node.bucket_index = storage::get_bucket_index(&full_flag_name, num_buckets);

            Ok(node)

        }

        // create test baseline, syntactic sugar

        fn new_expected(

            package_id: u32,

            flag_name: &str,

            flag_id: u32,

            next_offset: Option<u32>,

            bucket_index: u32,

        ) -> Self {

            Self {

                package_id,

                flag_name: flag_name.to_string(),

                flag_id,

                next_offset,

                bucket_index,

            }

        }

    }

    impl FlagTable {

        // test only method to deserialize back into the table struct

        fn from_bytes(bytes: &[u8]) -> Result<Self> {

            let header = FlagTableHeader::from_bytes(bytes)?;

            let num_flags = header.num_flags;

            let num_buckets = storage::get_table_size(num_flags)?;

            let mut head = header.as_bytes().len();

            let buckets = (0..num_buckets)

                .map(|_| match read_u32_from_bytes(bytes, &mut head).unwrap() {

                    0 => None,

                    val => Some(val),

                })

                .collect();

            let nodes = (0..num_flags)

                .map(|_| {

                    let node = FlagTableNode::from_bytes(&bytes[head..], num_buckets).unwrap();

                    head += node.as_bytes().len();

                    node

                })

                .collect();

            let table = Self { header, buckets, nodes };

            Ok(table)

        }

    }

    pub fn create_test_flag_table() -> Result<FlagTable> {

        let caches = parse_all_test_flags();

        let packages = group_flags_by_package(caches.iter());

        FlagTable::new("system", &packages)

    }

    #[test]

    // this test point locks down the table creation and each field

    fn test_table_contents() {

        let flag_table = create_test_flag_table();

        assert!(flag_table.is_ok());

        let header: &FlagTableHeader = &flag_table.as_ref().unwrap().header;

        let expected_header = FlagTableHeader {

            version: storage::FILE_VERSION,

            container: String::from("system"),

            file_size: 320,

            num_flags: 8,

            bucket_offset: 30,

            node_offset: 98,

        };

        assert_eq!(header, &expected_header);

        println!("{:?}", &flag_table.as_ref().unwrap().nodes);

        let buckets: &Vec<Option<u32>> = &flag_table.as_ref().unwrap().buckets;

        let expected_bucket: Vec<Option<u32>> = vec![

            Some(98),

            Some(124),

            None,

            None,

            None,

            Some(177),

            None,

            Some(203),

            None,

            Some(261),

            None,

            None,

            None,

            None,

            None,

            Some(293),

            None,

        ];

        assert_eq!(buckets, &expected_bucket);

        let nodes: &Vec<FlagTableNode> = &flag_table.as_ref().unwrap().nodes;

        assert_eq!(nodes.len(), 8);

        assert_eq!(nodes[0], FlagTableNode::new_expected(0, "enabled_ro", 1, None, 0));

        assert_eq!(nodes[1], FlagTableNode::new_expected(0, "enabled_rw", 2, Some(150), 1));

        assert_eq!(nodes[2], FlagTableNode::new_expected(1, "disabled_ro", 0, None, 1));

        assert_eq!(nodes[3], FlagTableNode::new_expected(2, "enabled_ro", 1, None, 5));

        assert_eq!(nodes[4], FlagTableNode::new_expected(1, "enabled_fixed_ro", 1, Some(235), 7));

        assert_eq!(nodes[5], FlagTableNode::new_expected(1, "enabled_ro", 2, None, 7));

        assert_eq!(nodes[6], FlagTableNode::new_expected(2, "enabled_fixed_ro", 0, None, 9));

        assert_eq!(nodes[7], FlagTableNode::new_expected(0, "disabled_rw", 0, None, 15));

    }

    #[test]

    // this test point locks down the table serialization

    fn test_serialization() {

        let flag_table = create_test_flag_table();

        assert!(flag_table.is_ok());

        let flag_table = flag_table.unwrap();

        let header: &FlagTableHeader = &flag_table.header;

        let reinterpreted_header = FlagTableHeader::from_bytes(&header.as_bytes());

        assert!(reinterpreted_header.is_ok());

        assert_eq!(header, &reinterpreted_header.unwrap());

        let nodes: &Vec<FlagTableNode> = &flag_table.nodes;

        let num_buckets = storage::get_table_size(header.num_flags).unwrap();

        for node in nodes.iter() {

            let reinterpreted_node = FlagTableNode::from_bytes(&node.as_bytes(), num_buckets);

            assert!(reinterpreted_node.is_ok());

            assert_eq!(node, &reinterpreted_node.unwrap());

        }

        let reinterpreted_table = FlagTable::from_bytes(&flag_table.as_bytes());

        assert!(reinterpreted_table.is_ok());

        assert_eq!(&flag_table, &reinterpreted_table.unwrap());

    }

}