// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
import { Buffer } from "../io/buffer.ts";
const DEFAULT_CHUNK_SIZE = 16_640;
const DEFAULT_BUFFER_SIZE = 32 * 1024;
function isCloser(value) {
    return typeof value === "object" && value != null && "close" in value && // deno-lint-ignore no-explicit-any
    typeof value["close"] === "function";
}
/** Create a `Deno.Reader` from an iterable of `Uint8Array`s.
 *
 * ```ts
 *      import { readerFromIterable, copy } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 *      const file = await Deno.open("metrics.txt", { write: true });
 *      const reader = readerFromIterable((async function* () {
 *        while (true) {
 *          await new Promise((r) => setTimeout(r, 1000));
 *          const message = `data: ${JSON.stringify(Deno.metrics())}\n\n`;
 *          yield new TextEncoder().encode(message);
 *        }
 *      })());
 *      await copy(reader, file);
 * ```
 */ export function readerFromIterable(iterable) {
    const iterator = iterable[Symbol.asyncIterator]?.() ?? iterable[Symbol.iterator]?.();
    const buffer = new Buffer();
    return {
        async read (p) {
            if (buffer.length == 0) {
                const result = await iterator.next();
                if (result.done) {
                    return null;
                } else {
                    if (result.value.byteLength <= p.byteLength) {
                        p.set(result.value);
                        return result.value.byteLength;
                    }
                    p.set(result.value.subarray(0, p.byteLength));
                    await writeAll(buffer, result.value.subarray(p.byteLength));
                    return p.byteLength;
                }
            } else {
                const n = await buffer.read(p);
                if (n == null) {
                    return this.read(p);
                }
                return n;
            }
        }
    };
}
/** Create a `Writer` from a `WritableStreamDefaultWriter`. */ export function writerFromStreamWriter(streamWriter) {
    return {
        async write (p) {
            await streamWriter.ready;
            await streamWriter.write(p);
            return p.length;
        }
    };
}
/** Create a `Reader` from a `ReadableStreamDefaultReader`. */ export function readerFromStreamReader(streamReader) {
    const buffer = new Buffer();
    return {
        async read (p) {
            if (buffer.empty()) {
                const res = await streamReader.read();
                if (res.done) {
                    return null; // EOF
                }
                await writeAll(buffer, res.value);
            }
            return buffer.read(p);
        }
    };
}
/** Create a `WritableStream` from a `Writer`. */ export function writableStreamFromWriter(writer, options = {}) {
    const { autoClose =true  } = options;
    return new WritableStream({
        async write (chunk, controller) {
            try {
                await writeAll(writer, chunk);
            } catch (e) {
                controller.error(e);
                if (isCloser(writer) && autoClose) {
                    writer.close();
                }
            }
        },
        close () {
            if (isCloser(writer) && autoClose) {
                writer.close();
            }
        },
        abort () {
            if (isCloser(writer) && autoClose) {
                writer.close();
            }
        }
    });
}
/** Create a `ReadableStream` from any kind of iterable.
 *
 * ```ts
 *      import { readableStreamFromIterable } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 *      const r1 = readableStreamFromIterable(["foo, bar, baz"]);
 *      const r2 = readableStreamFromIterable(async function* () {
 *        await new Promise(((r) => setTimeout(r, 1000)));
 *        yield "foo";
 *        await new Promise(((r) => setTimeout(r, 1000)));
 *        yield "bar";
 *        await new Promise(((r) => setTimeout(r, 1000)));
 *        yield "baz";
 *      }());
 * ```
 *
 * If the produced iterator (`iterable[Symbol.asyncIterator]()` or
 * `iterable[Symbol.iterator]()`) is a generator, or more specifically is found
 * to have a `.throw()` method on it, that will be called upon
 * `readableStream.cancel()`. This is the case for the second input type above:
 *
 * ```ts
 * import { readableStreamFromIterable } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * const r3 = readableStreamFromIterable(async function* () {
 *   try {
 *     yield "foo";
 *   } catch (error) {
 *     console.log(error); // Error: Cancelled by consumer.
 *   }
 * }());
 * const reader = r3.getReader();
 * console.log(await reader.read()); // { value: "foo", done: false }
 * await reader.cancel(new Error("Cancelled by consumer."));
 * ```
 */ export function readableStreamFromIterable(iterable) {
    const iterator = iterable[Symbol.asyncIterator]?.() ?? iterable[Symbol.iterator]?.();
    return new ReadableStream({
        async pull (controller) {
            const { value , done  } = await iterator.next();
            if (done) {
                controller.close();
            } else {
                controller.enqueue(value);
            }
        },
        async cancel (reason) {
            if (typeof iterator.throw == "function") {
                try {
                    await iterator.throw(reason);
                } catch  {}
            }
        }
    });
}
/**
 * Convert the generator function into a TransformStream.
 *
 * ```ts
 * import { readableStreamFromIterable, toTransformStream } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * const readable = readableStreamFromIterable([0, 1, 2])
 *   .pipeThrough(toTransformStream(async function* (src) {
 *     for await (const chunk of src) {
 *       yield chunk * 100;
 *     }
 *   }));
 *
 * for await (const chunk of readable) {
 *   console.log(chunk);
 * }
 * // output: 0, 100, 200
 * ```
 *
 * @param transformer A function to transform.
 * @param writableStrategy An object that optionally defines a queuing strategy for the stream.
 * @param readableStrategy An object that optionally defines a queuing strategy for the stream.
 */ export function toTransformStream(transformer, writableStrategy, readableStrategy) {
    const { writable , readable  } = new TransformStream(undefined, writableStrategy);
    const iterable = transformer(readable);
    const iterator = iterable[Symbol.asyncIterator]?.() ?? iterable[Symbol.iterator]?.();
    return {
        writable,
        readable: new ReadableStream({
            async pull (controller) {
                let result;
                try {
                    result = await iterator.next();
                } catch (error) {
                    // Propagate error to stream from iterator
                    // If the stream status is "errored", it will be thrown, but ignore.
                    await readable.cancel(error).catch(()=>{});
                    controller.error(error);
                    return;
                }
                if (result.done) {
                    controller.close();
                    return;
                }
                controller.enqueue(result.value);
            },
            async cancel (reason) {
                // Propagate cancellation to readable and iterator
                if (typeof iterator.throw == "function") {
                    try {
                        await iterator.throw(reason);
                    } catch  {
                    /* `iterator.throw()` always throws on site. We catch it. */ }
                }
                await readable.cancel(reason);
            }
        }, readableStrategy)
    };
}
/**
 * Create a `ReadableStream<Uint8Array>` from from a `Deno.Reader`.
 *
 * When the pull algorithm is called on the stream, a chunk from the reader
 * will be read.  When `null` is returned from the reader, the stream will be
 * closed along with the reader (if it is also a `Deno.Closer`).
 *
 * An example converting a `Deno.FsFile` into a readable stream:
 *
 * ```ts
 * import { readableStreamFromReader } from "https://deno.land/std@$STD_VERSION/streams/mod.ts";
 *
 * const file = await Deno.open("./file.txt", { read: true });
 * const fileStream = readableStreamFromReader(file);
 * ```
 */ export function readableStreamFromReader(reader, options = {}) {
    const { autoClose =true , chunkSize =DEFAULT_CHUNK_SIZE , strategy  } = options;
    return new ReadableStream({
        async pull (controller) {
            const chunk = new Uint8Array(chunkSize);
            try {
                const read = await reader.read(chunk);
                if (read === null) {
                    if (isCloser(reader) && autoClose) {
                        reader.close();
                    }
                    controller.close();
                    return;
                }
                controller.enqueue(chunk.subarray(0, read));
            } catch (e) {
                controller.error(e);
                if (isCloser(reader)) {
                    reader.close();
                }
            }
        },
        cancel () {
            if (isCloser(reader) && autoClose) {
                reader.close();
            }
        }
    }, strategy);
}
/** Read Reader `r` until EOF (`null`) and resolve to the content as
 * Uint8Array`.
 *
 * ```ts
 * import { Buffer } from "https://deno.land/std@$STD_VERSION/io/buffer.ts";
 * import { readAll } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * // Example from stdin
 * const stdinContent = await readAll(Deno.stdin);
 *
 * // Example from file
 * const file = await Deno.open("my_file.txt", {read: true});
 * const myFileContent = await readAll(file);
 * file.close();
 *
 * // Example from buffer
 * const myData = new Uint8Array(100);
 * // ... fill myData array with data
 * const reader = new Buffer(myData.buffer);
 * const bufferContent = await readAll(reader);
 * ```
 */ export async function readAll(r) {
    const buf = new Buffer();
    await buf.readFrom(r);
    return buf.bytes();
}
/** Synchronously reads Reader `r` until EOF (`null`) and returns the content
 * as `Uint8Array`.
 *
 * ```ts
 * import { Buffer } from "https://deno.land/std@$STD_VERSION/io/buffer.ts";
 * import { readAllSync } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * // Example from stdin
 * const stdinContent = readAllSync(Deno.stdin);
 *
 * // Example from file
 * const file = Deno.openSync("my_file.txt", {read: true});
 * const myFileContent = readAllSync(file);
 * file.close();
 *
 * // Example from buffer
 * const myData = new Uint8Array(100);
 * // ... fill myData array with data
 * const reader = new Buffer(myData.buffer);
 * const bufferContent = readAllSync(reader);
 * ```
 */ export function readAllSync(r) {
    const buf = new Buffer();
    buf.readFromSync(r);
    return buf.bytes();
}
/** Write all the content of the array buffer (`arr`) to the writer (`w`).
 *
 * ```ts
 * import { Buffer } from "https://deno.land/std@$STD_VERSION/io/buffer.ts";
 * import { writeAll } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";

 * // Example writing to stdout
 * let contentBytes = new TextEncoder().encode("Hello World");
 * await writeAll(Deno.stdout, contentBytes);
 *
 * // Example writing to file
 * contentBytes = new TextEncoder().encode("Hello World");
 * const file = await Deno.open('test.file', {write: true});
 * await writeAll(file, contentBytes);
 * file.close();
 *
 * // Example writing to buffer
 * contentBytes = new TextEncoder().encode("Hello World");
 * const writer = new Buffer();
 * await writeAll(writer, contentBytes);
 * console.log(writer.bytes().length);  // 11
 * ```
 */ export async function writeAll(w, arr) {
    let nwritten = 0;
    while(nwritten < arr.length){
        nwritten += await w.write(arr.subarray(nwritten));
    }
}
/** Synchronously write all the content of the array buffer (`arr`) to the
 * writer (`w`).
 *
 * ```ts
 * import { Buffer } from "https://deno.land/std@$STD_VERSION/io/buffer.ts";
 * import { writeAllSync } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * // Example writing to stdout
 * let contentBytes = new TextEncoder().encode("Hello World");
 * writeAllSync(Deno.stdout, contentBytes);
 *
 * // Example writing to file
 * contentBytes = new TextEncoder().encode("Hello World");
 * const file = Deno.openSync('test.file', {write: true});
 * writeAllSync(file, contentBytes);
 * file.close();
 *
 * // Example writing to buffer
 * contentBytes = new TextEncoder().encode("Hello World");
 * const writer = new Buffer();
 * writeAllSync(writer, contentBytes);
 * console.log(writer.bytes().length);  // 11
 * ```
 */ export function writeAllSync(w, arr) {
    let nwritten = 0;
    while(nwritten < arr.length){
        nwritten += w.writeSync(arr.subarray(nwritten));
    }
}
/** Turns a Reader, `r`, into an async iterator.
 *
 * ```ts
 * import { iterateReader } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * let f = await Deno.open("/etc/passwd");
 * for await (const chunk of iterateReader(f)) {
 *   console.log(chunk);
 * }
 * f.close();
 * ```
 *
 * Second argument can be used to tune size of a buffer.
 * Default size of the buffer is 32kB.
 *
 * ```ts
 * import { iterateReader } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * let f = await Deno.open("/etc/passwd");
 * const it = iterateReader(f, {
 *   bufSize: 1024 * 1024
 * });
 * for await (const chunk of it) {
 *   console.log(chunk);
 * }
 * f.close();
 * ```
 */ export async function* iterateReader(r, options) {
    const bufSize = options?.bufSize ?? DEFAULT_BUFFER_SIZE;
    const b = new Uint8Array(bufSize);
    while(true){
        const result = await r.read(b);
        if (result === null) {
            break;
        }
        yield b.slice(0, result);
    }
}
/** Turns a ReaderSync, `r`, into an iterator.
 *
 * ```ts
 * import { iterateReaderSync } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * let f = Deno.openSync("/etc/passwd");
 * for (const chunk of iterateReaderSync(f)) {
 *   console.log(chunk);
 * }
 * f.close();
 * ```
 *
 * Second argument can be used to tune size of a buffer.
 * Default size of the buffer is 32kB.
 *
 * ```ts
 * import { iterateReaderSync } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";

 * let f = await Deno.open("/etc/passwd");
 * const iter = iterateReaderSync(f, {
 *   bufSize: 1024 * 1024
 * });
 * for (const chunk of iter) {
 *   console.log(chunk);
 * }
 * f.close();
 * ```
 *
 * Iterator uses an internal buffer of fixed size for efficiency; it returns
 * a view on that buffer on each iteration. It is therefore caller's
 * responsibility to copy contents of the buffer if needed; otherwise the
 * next iteration will overwrite contents of previously returned chunk.
 */ export function* iterateReaderSync(r, options) {
    const bufSize = options?.bufSize ?? DEFAULT_BUFFER_SIZE;
    const b = new Uint8Array(bufSize);
    while(true){
        const result = r.readSync(b);
        if (result === null) {
            break;
        }
        yield b.slice(0, result);
    }
}
/** Copies from `src` to `dst` until either EOF (`null`) is read from `src` or
 * an error occurs. It resolves to the number of bytes copied or rejects with
 * the first error encountered while copying.
 *
 * ```ts
 * import { copy } from "https://deno.land/std@$STD_VERSION/streams/conversion.ts";
 *
 * const source = await Deno.open("my_file.txt");
 * const bytesCopied1 = await copy(source, Deno.stdout);
 * const destination = await Deno.create("my_file_2.txt");
 * const bytesCopied2 = await copy(source, destination);
 * ```
 *
 * @param src The source to copy from
 * @param dst The destination to copy to
 * @param options Can be used to tune size of the buffer. Default size is 32kB
 */ export async function copy(src, dst, options) {
    let n = 0;
    const bufSize = options?.bufSize ?? DEFAULT_BUFFER_SIZE;
    const b = new Uint8Array(bufSize);
    let gotEOF = false;
    while(gotEOF === false){
        const result = await src.read(b);
        if (result === null) {
            gotEOF = true;
        } else {
            let nwritten = 0;
            while(nwritten < result){
                nwritten += await dst.write(b.subarray(nwritten, result));
            }
            n += nwritten;
        }
    }
    return n;
}
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