Merge pull request 'Full Docker code refactor' (#183) from Chewing_Bever/vieter:docker-rework into dev

Reviewed-on: vieter/vieter#183
Jef Roosens 2022-05-16 15:44:35 +02:00
commit 92f73ad364
14 changed files with 523 additions and 195 deletions

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@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
* Web API for adding & querying build logs
* CLI commands to access build logs API
* Cron build logs are uploaded to above API
* Proper ASCII table output in CLI
### Changed
@ -20,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
* Official Arch packages are now split between `vieter` & `vieter-git`
* `vieter` is the latest release
* `vieter-git` is the latest commit on the dev branch
* Full refactor of Docker socket code
## [0.3.0-alpha.1](https://git.rustybever.be/vieter/vieter/src/tag/0.3.0-alpha.1)

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@ -6,10 +6,13 @@ import time
import os
import db
import client
import strings
import util
const container_build_dir = '/build'
const build_image_repo = 'vieter-build'
const (
container_build_dir = '/build'
build_image_repo = 'vieter-build'
)
// create_build_image creates a builder image given some base image which can
// then be used to build & package Arch images. It mostly just updates the
@ -17,6 +20,12 @@ const build_image_repo = 'vieter-build'
// makepkg with. The base image should be some Linux distribution that uses
// Pacman as its package manager.
pub fn create_build_image(base_image string) ?string {
mut dd := docker.new_conn()?
defer {
dd.close() or {}
}
commands := [
// Update repos & install required packages
'pacman -Syu --needed --noconfirm base-devel git'
@ -46,14 +55,15 @@ pub fn create_build_image(base_image string) ?string {
image_tag := if image_parts.len > 1 { image_parts[1] } else { 'latest' }
// We pull the provided image
docker.pull_image(image_name, image_tag)?
dd.pull_image(image_name, image_tag)?
id := docker.create_container(c)?
docker.start_container(id)?
id := dd.create_container(c)?.id
// id := docker.create_container(c)?
dd.start_container(id)?
// This loop waits until the container has stopped, so we can remove it after
for {
data := docker.inspect_container(id)?
data := dd.inspect_container(id)?
if !data.state.running {
break
@ -67,8 +77,8 @@ pub fn create_build_image(base_image string) ?string {
// TODO also add the base image's name into the image name to prevent
// conflicts.
tag := time.sys_mono_now().str()
image := docker.create_image_from_container(id, 'vieter-build', tag)?
docker.remove_container(id)?
image := dd.create_image_from_container(id, 'vieter-build', tag)?
dd.remove_container(id)?
return image.id
}
@ -85,6 +95,12 @@ pub:
// provided GitRepo. The base image ID should be of an image previously created
// by create_build_image. It returns the logs of the container.
pub fn build_repo(address string, api_key string, base_image_id string, repo &db.GitRepo) ?BuildResult {
mut dd := docker.new_conn()?
defer {
dd.close() or {}
}
build_arch := os.uname().machine
// TODO what to do with PKGBUILDs that build multiple packages?
@ -112,27 +128,31 @@ pub fn build_repo(address string, api_key string, base_image_id string, repo &db
user: 'builder:builder'
}
id := docker.create_container(c)?
docker.start_container(id)?
id := dd.create_container(c)?.id
dd.start_container(id)?
mut data := docker.inspect_container(id)?
mut data := dd.inspect_container(id)?
// This loop waits until the container has stopped, so we can remove it after
for data.state.running {
time.sleep(1 * time.second)
data = docker.inspect_container(id)?
data = dd.inspect_container(id)?
}
logs := docker.get_container_logs(id)?
mut logs_stream := dd.get_container_logs(id)?
docker.remove_container(id)?
// Read in the entire stream
mut logs_builder := strings.new_builder(10 * 1024)
util.reader_to_writer(mut logs_stream, mut logs_builder)?
dd.remove_container(id)?
return BuildResult{
start_time: data.state.start_time
end_time: data.state.end_time
exit_code: data.state.exit_code
logs: logs
logs: logs_builder.str()
}
}
@ -150,7 +170,14 @@ fn build(conf Config, repo_id int) ? {
res := build_repo(conf.address, conf.api_key, image_id, repo)?
println('Removing build image...')
docker.remove_image(image_id)?
mut dd := docker.new_conn()?
defer {
dd.close() or {}
}
dd.remove_image(image_id)?
println('Uploading logs to Vieter...')
c.add_build_log(repo.id, res.start_time, res.end_time, build_arch, res.exit_code,

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@ -253,14 +253,21 @@ fn (mut d Daemon) rebuild_base_image() bool {
fn (mut d Daemon) clean_old_base_images() {
mut i := 0
mut dd := docker.new_conn() or {
d.lerror('Failed to connect to Docker socket.')
return
}
defer {
dd.close() or {}
}
for i < d.builder_images.len - 1 {
// For each builder image, we try to remove it by calling the Docker
// API. If the function returns an error or false, that means the image
// wasn't deleted. Therefore, we move the index over. If the function
// returns true, the array's length has decreased by one so we don't
// move the index.
if !docker.remove_image(d.builder_images[i]) or { false } {
i += 1
}
dd.remove_image(d.builder_images[i]) or { i += 1 }
}
}

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@ -0,0 +1,3 @@
This module implements part of the Docker Engine API v1.41
([documentation](https://docs.docker.com/engine/api/v1.41/)) using socket-based
HTTP communication.

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@ -3,17 +3,10 @@ module docker
import json
import net.urllib
import time
import net.http { Method }
struct Container {
id string [json: Id]
names []string [json: Names]
}
// containers returns a list of all currently running containers
pub fn containers() ?[]Container {
res := request('GET', urllib.parse('/v1.41/containers/json')?)?
return json.decode([]Container, res.text) or {}
struct DockerError {
message string
}
pub struct NewContainer {
@ -26,27 +19,37 @@ pub struct NewContainer {
}
struct CreatedContainer {
pub:
id string [json: Id]
warnings []string [json: Warnings]
}
// create_container creates a container defined by the given configuration. If
// successful, it returns the ID of the newly created container.
pub fn create_container(c &NewContainer) ?string {
res := request_with_json('POST', urllib.parse('/v1.41/containers/create')?, c)?
// create_container creates a new container with the given config.
pub fn (mut d DockerConn) create_container(c NewContainer) ?CreatedContainer {
d.send_request_with_json(Method.post, urllib.parse('/v1.41/containers/create')?, c)?
head, res := d.read_response()?
if res.status_code != 201 {
return error('Failed to create container.')
if head.status_code != 201 {
data := json.decode(DockerError, res)?
return error(data.message)
}
return json.decode(CreatedContainer, res.text)?.id
data := json.decode(CreatedContainer, res)?
return data
}
// start_container starts a container with a given ID. It returns whether the
// container was started or not.
pub fn start_container(id string) ?bool {
res := request('POST', urllib.parse('/v1.41/containers/$id/start')?)?
// start_container starts the container with the given id.
pub fn (mut d DockerConn) start_container(id string) ? {
d.send_request(Method.post, urllib.parse('/v1.41/containers/$id/start')?)?
head, body := d.read_response()?
return res.status_code == 204
if head.status_code != 204 {
data := json.decode(DockerError, body)?
return error(data.message)
}
}
struct ContainerInspect {
@ -67,16 +70,18 @@ pub mut:
end_time time.Time [skip]
}
// inspect_container returns the result of inspecting a container with a given
// ID.
pub fn inspect_container(id string) ?ContainerInspect {
res := request('GET', urllib.parse('/v1.41/containers/$id/json')?)?
// inspect_container returns detailed information for a given container.
pub fn (mut d DockerConn) inspect_container(id string) ?ContainerInspect {
d.send_request(Method.get, urllib.parse('/v1.41/containers/$id/json')?)?
head, body := d.read_response()?
if res.status_code != 200 {
return error('Failed to inspect container.')
if head.status_code != 200 {
data := json.decode(DockerError, body)?
return error(data.message)
}
mut data := json.decode(ContainerInspect, res.text)?
mut data := json.decode(ContainerInspect, body)?
data.state.start_time = time.parse_rfc3339(data.state.start_time_str)?
@ -87,31 +92,31 @@ pub fn inspect_container(id string) ?ContainerInspect {
return data
}
// remove_container removes a container with a given ID.
pub fn remove_container(id string) ?bool {
res := request('DELETE', urllib.parse('/v1.41/containers/$id')?)?
// remove_container removes the container with the given id.
pub fn (mut d DockerConn) remove_container(id string) ? {
d.send_request(Method.delete, urllib.parse('/v1.41/containers/$id')?)?
head, body := d.read_response()?
return res.status_code == 204
if head.status_code != 204 {
data := json.decode(DockerError, body)?
return error(data.message)
}
}
// get_container_logs retrieves the logs for a Docker container, both stdout &
// stderr.
pub fn get_container_logs(id string) ?string {
res := request('GET', urllib.parse('/v1.41/containers/$id/logs?stdout=true&stderr=true')?)?
mut res_bytes := res.text.bytes()
// get_container_logs returns a reader object allowing access to the
// container's logs.
pub fn (mut d DockerConn) get_container_logs(id string) ?&StreamFormatReader {
d.send_request(Method.get, urllib.parse('/v1.41/containers/$id/logs?stdout=true&stderr=true')?)?
head := d.read_response_head()?
// Docker uses a special "stream" format for their logs, so we have to
// clean up the data.
mut index := 0
if head.status_code != 200 {
content_length := head.header.get(http.CommonHeader.content_length)?.int()
body := d.read_response_body(content_length)?
data := json.decode(DockerError, body)?
for index < res_bytes.len {
// The reverse is required because V reads in the bytes differently
t := res_bytes[index + 4..index + 8].reverse()
len_length := unsafe { *(&u32(&t[0])) }
res_bytes.delete_many(index, 8)
index += int(len_length)
return error(data.message)
}
return res_bytes.bytestr()
return d.get_stream_format_reader()
}

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@ -1,97 +1,137 @@
module docker
import net.unix
import net.urllib
import io
import net.http
import strings
import net.urllib
import json
import util
const socket = '/var/run/docker.sock'
const (
socket = '/var/run/docker.sock'
buf_len = 10 * 1024
http_separator = [u8(`\r`), `\n`, `\r`, `\n`]
http_chunk_separator = [u8(`\r`), `\n`]
)
const buf_len = 1024
pub struct DockerConn {
mut:
socket &unix.StreamConn
reader &io.BufferedReader
}
// send writes a request to the Docker socket, waits for a response & returns
// it.
fn send(req &string) ?http.Response {
// Open a connection to the socket
mut s := unix.connect_stream(docker.socket) or {
return error('Failed to connect to socket ${docker.socket}.')
// new_conn creates a new connection to the Docker daemon.
pub fn new_conn() ?&DockerConn {
s := unix.connect_stream(docker.socket)?
d := &DockerConn{
socket: s
reader: io.new_buffered_reader(reader: s)
}
defer {
// This or is required because otherwise, the V compiler segfaults for
// some reason
// https://github.com/vlang/v/issues/13534
s.close() or {}
}
return d
}
// Write the request to the socket
s.write_string(req) or { return error('Failed to write request to socket ${docker.socket}.') }
// close closes the underlying socket connection.
pub fn (mut d DockerConn) close() ? {
d.socket.close()?
}
s.wait_for_write()?
// send_request sends an HTTP request without body.
pub fn (mut d DockerConn) send_request(method http.Method, url urllib.URL) ? {
req := '$method $url.request_uri() HTTP/1.1\nHost: localhost\n\n'
mut c := 0
mut buf := []u8{len: docker.buf_len}
d.socket.write_string(req)?
// When starting a new request, the reader needs to be reset.
d.reader = io.new_buffered_reader(reader: d.socket)
}
// send_request_with_body sends an HTTP request with the given body.
pub fn (mut d DockerConn) send_request_with_body(method http.Method, url urllib.URL, content_type string, body string) ? {
req := '$method $url.request_uri() HTTP/1.1\nHost: localhost\nContent-Type: $content_type\nContent-Length: $body.len\n\n$body\n\n'
d.socket.write_string(req)?
// When starting a new request, the reader needs to be reset.
d.reader = io.new_buffered_reader(reader: d.socket)
}
// send_request_with_json<T> is a convenience wrapper around
// send_request_with_body that encodes the input as JSON.
pub fn (mut d DockerConn) send_request_with_json<T>(method http.Method, url urllib.URL, data &T) ? {
body := json.encode(data)
return d.send_request_with_body(method, url, 'application/json', body)
}
// read_response_head consumes the socket's contents until it encounters
// '\r\n\r\n', after which it parses the response as an HTTP response.
// Importantly, this function never consumes the reader past the HTTP
// separator, so the body can be read fully later on.
pub fn (mut d DockerConn) read_response_head() ?http.Response {
mut res := []u8{}
for {
c = s.read(mut buf) or { return error('Failed to read data from socket ${docker.socket}.') }
res << buf[..c]
util.read_until_separator(mut d.reader, mut res, docker.http_separator)?
if c < docker.buf_len {
break
}
}
// After reading the first part of the response, we parse it into an HTTP
// response. If it isn't chunked, we return early with the data.
parsed := http.parse_response(res.bytestr()) or {
return error('Failed to parse HTTP response from socket ${docker.socket}.')
}
if parsed.header.get(http.CommonHeader.transfer_encoding) or { '' } != 'chunked' {
return parsed
}
// We loop until we've encountered the end of the chunked response
// A chunked HTTP response always ends with '0\r\n\r\n'.
for res.len < 5 || res#[-5..] != [u8(`0`), `\r`, `\n`, `\r`, `\n`] {
// Wait for the server to respond
s.wait_for_write()?
for {
c = s.read(mut buf) or {
return error('Failed to read data from socket ${docker.socket}.')
}
res << buf[..c]
if c < docker.buf_len {
break
}
}
}
// Decode chunked response
return http.parse_response(res.bytestr())
}
// request_with_body sends a request to the Docker socket with the given body.
fn request_with_body(method string, url urllib.URL, content_type string, body string) ?http.Response {
req := '$method $url.request_uri() HTTP/1.1\nHost: localhost\nContent-Type: $content_type\nContent-Length: $body.len\n\n$body\n\n'
// read_response_body reads `length` bytes from the stream. It can be used when
// the response encoding isn't chunked to fully read it.
pub fn (mut d DockerConn) read_response_body(length int) ?string {
if length == 0 {
return ''
}
return send(req)
mut buf := []u8{len: docker.buf_len}
mut c := 0
mut builder := strings.new_builder(docker.buf_len)
for builder.len < length {
c = d.reader.read(mut buf) or { break }
builder.write(buf[..c])?
}
return builder.str()
}
// request sends a request to the Docker socket with an empty body.
fn request(method string, url urllib.URL) ?http.Response {
req := '$method $url.request_uri() HTTP/1.1\nHost: localhost\n\n'
// read_response is a convenience function which always consumes the entire
// response & returns it. It should only be used when we're certain that the
// result isn't too large.
pub fn (mut d DockerConn) read_response() ?(http.Response, string) {
head := d.read_response_head()?
return send(req)
if head.header.get(http.CommonHeader.transfer_encoding) or { '' } == 'chunked' {
mut builder := strings.new_builder(1024)
mut body := d.get_chunked_response_reader()
util.reader_to_writer(mut body, mut builder)?
return head, builder.str()
}
content_length := head.header.get(http.CommonHeader.content_length)?.int()
res := d.read_response_body(content_length)?
return head, res
}
// request_with_json<T> sends a request to the Docker socket with a given JSON
// payload
pub fn request_with_json<T>(method string, url urllib.URL, data &T) ?http.Response {
body := json.encode(data)
// get_chunked_response_reader returns a ChunkedResponseReader using the socket
// as reader.
pub fn (mut d DockerConn) get_chunked_response_reader() &ChunkedResponseReader {
r := new_chunked_response_reader(d.reader)
return request_with_body(method, url, 'application/json', body)
return r
}
// get_stream_format_reader returns a StreamFormatReader using the socket as
// reader.
pub fn (mut d DockerConn) get_stream_format_reader() &StreamFormatReader {
r := new_chunked_response_reader(d.reader)
r2 := new_stream_format_reader(r)
return r2
}

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@ -1,6 +1,6 @@
module docker
import net.http
import net.http { Method }
import net.urllib
import json
@ -9,26 +9,53 @@ pub:
id string [json: Id]
}
// pull_image pulls tries to pull the image for the given image & tag
pub fn pull_image(image string, tag string) ?http.Response {
return request('POST', urllib.parse('/v1.41/images/create?fromImage=$image&tag=$tag')?)
}
// pull_image pulls the given image:tag.
pub fn (mut d DockerConn) pull_image(image string, tag string) ? {
d.send_request(Method.post, urllib.parse('/v1.41/images/create?fromImage=$image&tag=$tag')?)?
head := d.read_response_head()?
// create_image_from_container creates a new image from a container with the
// given repo & tag, given the container's ID.
pub fn create_image_from_container(id string, repo string, tag string) ?Image {
res := request('POST', urllib.parse('/v1.41/commit?container=$id&repo=$repo&tag=$tag')?)?
if head.status_code != 200 {
content_length := head.header.get(http.CommonHeader.content_length)?.int()
body := d.read_response_body(content_length)?
data := json.decode(DockerError, body)?
if res.status_code != 201 {
return error('Failed to create image from container.')
return error(data.message)
}
return json.decode(Image, res.text) or {}
// Keep reading the body until the pull has completed
mut body := d.get_chunked_response_reader()
mut buf := []u8{len: 1024}
for {
body.read(mut buf) or { break }
}
}
// remove_image removes the image with the given ID.
pub fn remove_image(id string) ?bool {
res := request('DELETE', urllib.parse('/v1.41/images/$id')?)?
// create_image_from_container creates a new image from a container.
pub fn (mut d DockerConn) create_image_from_container(id string, repo string, tag string) ?Image {
d.send_request(Method.post, urllib.parse('/v1.41/commit?container=$id&repo=$repo&tag=$tag')?)?
head, body := d.read_response()?
return res.status_code == 200
if head.status_code != 201 {
data := json.decode(DockerError, body)?
return error(data.message)
}
data := json.decode(Image, body)?
return data
}
// remove_image removes the image with the given id.
pub fn (mut d DockerConn) remove_image(id string) ? {
d.send_request(Method.delete, urllib.parse('/v1.41/images/$id')?)?
head, body := d.read_response()?
if head.status_code != 200 {
data := json.decode(DockerError, body)?
return error(data.message)
}
}

135
src/docker/stream.v 100644
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@ -0,0 +1,135 @@
module docker
import io
import util
import encoding.binary
import encoding.hex
// ChunkedResponseReader parses an underlying HTTP chunked response, exposing
// it as if it was a continuous stream of data.
struct ChunkedResponseReader {
mut:
reader io.BufferedReader
bytes_left_in_chunk u64
started bool
}
// new_chunked_response_reader creates a new ChunkedResponseReader on the heap
// with the provided reader.
pub fn new_chunked_response_reader(reader io.BufferedReader) &ChunkedResponseReader {
r := &ChunkedResponseReader{
reader: reader
}
return r
}
// read satisfies the io.Reader interface.
pub fn (mut r ChunkedResponseReader) read(mut buf []u8) ?int {
if r.bytes_left_in_chunk == 0 {
// An io.BufferedReader always returns none if its stream has
// ended.
r.bytes_left_in_chunk = r.read_chunk_size()?
}
mut c := 0
// Make sure we don't read more than we can safely read. This is to avoid
// the underlying reader from becoming out of sync with our parsing:
if buf.len > r.bytes_left_in_chunk {
c = r.reader.read(mut buf[..r.bytes_left_in_chunk])?
} else {
c = r.reader.read(mut buf)?
}
r.bytes_left_in_chunk -= u64(c)
return c
}
// read_chunk_size advances the reader & reads the size of the next HTTP chunk.
// This function should only be called if the previous chunk has been
// completely consumed.
fn (mut r ChunkedResponseReader) read_chunk_size() ?u64 {
if r.started {
mut buf := []u8{len: 2}
// Each chunk ends with a `\r\n` which we want to skip first
r.reader.read(mut buf)?
}
r.started = true
mut res := []u8{}
util.read_until_separator(mut r.reader, mut res, http_chunk_separator)?
// The length of the next chunk is provided as a hexadecimal
mut num_data := hex.decode(res#[..-2].bytestr())?
for num_data.len < 8 {
num_data.insert(0, 0)
}
num := binary.big_endian_u64(num_data)
// This only occurs for the very last chunk, which always reports a size of
// 0.
if num == 0 {
return none
}
return num
}
// StreamFormatReader parses an underlying stream of Docker logs, removing the
// header bytes.
struct StreamFormatReader {
mut:
reader ChunkedResponseReader
bytes_left_in_chunk u32
}
// new_stream_format_reader creates a new StreamFormatReader using the given
// reader.
pub fn new_stream_format_reader(reader ChunkedResponseReader) &StreamFormatReader {
r := &StreamFormatReader{
reader: reader
}
return r
}
// read satisfies the io.Reader interface.
pub fn (mut r StreamFormatReader) read(mut buf []u8) ?int {
if r.bytes_left_in_chunk == 0 {
r.bytes_left_in_chunk = r.read_chunk_size()?
}
mut c := 0
if buf.len > r.bytes_left_in_chunk {
c = r.reader.read(mut buf[..r.bytes_left_in_chunk])?
} else {
c = r.reader.read(mut buf)?
}
r.bytes_left_in_chunk -= u32(c)
return c
}
// read_chunk_size advances the reader & reads the header bytes for the length
// of the next chunk.
fn (mut r StreamFormatReader) read_chunk_size() ?u32 {
mut buf := []u8{len: 8}
r.reader.read(mut buf)?
num := binary.big_endian_u32(buf[4..])
if num == 0 {
return none
}
return num
}

7
src/env/README.md vendored 100644
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@ -0,0 +1,7 @@
This module provides a framework for parsing a configuration, defined as a
struct, from both a TOML configuration file & environment variables. Some
notable features are:
* Overwrite values in config file using environment variables
* Allow default values in config struct
* Read environment variable value from file

18
src/env/env.v vendored
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@ -3,13 +3,19 @@ module env
import os
import toml
// The prefix that every environment variable should have
const prefix = 'VIETER_'
// The suffix an environment variable in order for it to be loaded from a file
// instead
const file_suffix = '_FILE'
const (
// The prefix that every environment variable should have
prefix = 'VIETER_'
// The suffix an environment variable in order for it to be loaded from a file
// instead
file_suffix = '_FILE'
)
// get_env_var tries to read the contents of the given environment variable. It
// looks for either `${env.prefix}${field_name.to_upper()}` or
// `${env.prefix}${field_name.to_upper()}${env.file_suffix}`, returning the
// contents of the file instead if the latter. If both or neither exist, the
// function returns an error.
fn get_env_var(field_name string) ?string {
env_var_name := '$env.prefix$field_name.to_upper()'
env_file_name := '$env.prefix$field_name.to_upper()$env.file_suffix'

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@ -31,7 +31,7 @@ fn main() {
logs.cmd(),
]
}
app.setup()
app.parse(os.args)
return
}

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@ -0,0 +1,2 @@
This module defines a few useful functions used throughout the codebase that
don't specifically fit inside a module.

95
src/util/stream.v 100644
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@ -0,0 +1,95 @@
// Functions for interacting with `io.Reader` & `io.Writer` objects.
module util
import io
import os
// reader_to_writer tries to consume the entire reader & write it to the writer.
pub fn reader_to_writer(mut reader io.Reader, mut writer io.Writer) ? {
mut buf := []u8{len: 10 * 1024}
for {
bytes_read := reader.read(mut buf) or { break }
mut bytes_written := 0
for bytes_written < bytes_read {
c := writer.write(buf[bytes_written..bytes_read]) or { break }
bytes_written += c
}
}
}
// reader_to_file writes the contents of a BufferedReader to a file
pub fn reader_to_file(mut reader io.BufferedReader, length int, path string) ? {
mut file := os.create(path)?
defer {
file.close()
}
mut buf := []u8{len: reader_buf_size}
mut bytes_left := length
// Repeat as long as the stream still has data
for bytes_left > 0 {
// TODO check if just breaking here is safe
bytes_read := reader.read(mut buf) or { break }
bytes_left -= bytes_read
mut to_write := bytes_read
for to_write > 0 {
// TODO don't just loop infinitely here
bytes_written := file.write(buf[bytes_read - to_write..bytes_read]) or { continue }
// file.flush()
to_write = to_write - bytes_written
}
}
}
// match_array_in_array<T> returns how many elements of a2 overlap with a1. For
// example, if a1 = "abcd" & a2 = "cd", the result will be 2. If the match is
// not at the end of a1, the result is 0.
pub fn match_array_in_array<T>(a1 []T, a2 []T) int {
mut i := 0
mut match_len := 0
for i + match_len < a1.len {
if a1[i + match_len] == a2[match_len] {
match_len += 1
} else {
i += match_len + 1
match_len = 0
}
}
return match_len
}
// read_until_separator consumes an io.Reader until it encounters some
// separator array. The data read is stored inside the provided res array.
pub fn read_until_separator(mut reader io.Reader, mut res []u8, sep []u8) ? {
mut buf := []u8{len: sep.len}
for {
c := reader.read(mut buf)?
res << buf[..c]
match_len := match_array_in_array(buf[..c], sep)
if match_len == sep.len {
break
}
if match_len > 0 {
match_left := sep.len - match_len
c2 := reader.read(mut buf[..match_left])?
res << buf[..c2]
if buf[..c2] == sep[match_len..] {
break
}
}
}
}

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@ -1,13 +1,13 @@
module util
import os
import io
import crypto.md5
import crypto.sha256
const reader_buf_size = 1_000_000
const prefixes = ['B', 'KB', 'MB', 'GB']
const (
reader_buf_size = 1_000_000
prefixes = ['B', 'KB', 'MB', 'GB']
)
// Dummy struct to work around the fact that you can only share structs, maps &
// arrays
@ -23,34 +23,6 @@ pub fn exit_with_message(code int, msg string) {
exit(code)
}
// reader_to_file writes the contents of a BufferedReader to a file
pub fn reader_to_file(mut reader io.BufferedReader, length int, path string) ? {
mut file := os.create(path)?
defer {
file.close()
}
mut buf := []u8{len: util.reader_buf_size}
mut bytes_left := length
// Repeat as long as the stream still has data
for bytes_left > 0 {
// TODO check if just breaking here is safe
bytes_read := reader.read(mut buf) or { break }
bytes_left -= bytes_read
mut to_write := bytes_read
for to_write > 0 {
// TODO don't just loop infinitely here
bytes_written := file.write(buf[bytes_read - to_write..bytes_read]) or { continue }
// file.flush()
to_write = to_write - bytes_written
}
}
}
// hash_file returns the md5 & sha256 hash of a given file
// TODO actually implement sha256
pub fn hash_file(path &string) ?(string, string) {