Zig

Amazon S3 List More than 1000 Objects in Bucket

See more Amazon S3 Examples

S3 limits the size of the "List Objects" response to 1000 objects. To retrieve a listing of all of the objects in a bucket containing more than 1000 objects, we'll need to send several requests using continuation tokens. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // This example assumes the Chilkat HTTP API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    const http = try chilkat.Http.init();
    defer http.deinit();

    // Insert your access key here:
    http.setAwsAccessKey("AWS_ACCESS_KEY");

    // Insert your secret key here:
    http.setAwsSecretKey("AWS_SECRET_KEY");

    // For the example, we'll get a listing containing approx. 25 objects
    // using continuation tokens with an artificially low max-keys set to 5.
    // (You may omit the max-keys query parameter to get the default 1000 maximum
    // number of keys per request.)

    const sb_continuation_token = try chilkat.StringBuilder.init();
    defer sb_continuation_token.deinit();
    var b_get_more: bool = true;
    const sb_uri = try chilkat.StringBuilder.init();
    defer sb_uri.deinit();
    const xml = try chilkat.Xml.init();
    defer xml.deinit();

    var item_key: [:0]const u8 = "";
    var item_size_decimal_str: [:0]const u8 = "";
    var last_mod_timestamp: [:0]const u8 = "";
    const dt = try chilkat.DateTime.init();
    defer dt.deinit();
    const dt_obj = try chilkat.DtObj.init();
    defer dt_obj.deinit();

    while (b_get_more) {
        // Make sure to set the "list-type" query param equal to "2".
        // This chooses the GET Bucket (List Objects) Version 2 of the method.

        // IMPORTANT: You must include the max-keys param to get a response with a continuation token.
        // S3 limits the number of objects in a single response to 1000. Therefore, your max-keys
        // can be up to 1000.  If, for example, you have 2000 objects and do not specify
        // max-keys, then the response will contain 1000 objects with no continuation token.
        sb_uri.setString("chilkat100?list-type=2&max-keys=5") catch {};
        if (sb_continuation_token.getLength() > 0) {
            sb_uri.append("&continuation-token=") catch {};
            sb_uri.append(try sb_continuation_token.getEncoded(alloc, "url", "utf-8")) catch {};
        }

        const str_xml = http.s3ListBucketObjects(alloc, try sb_uri.getAsString(alloc)) catch {
            std.debug.print("{s}\n", .{try http.getLastErrorText(alloc)});
            return;
        };

        std.debug.print("Response status code = {d}\n", .{http.getLastStatus()});

        xml.loadXml(str_xml) catch {
            std.debug.print("{s}\n", .{try xml.getLastErrorText(alloc)});
            return;
        };

        // If the response status code was not 200, then the XML response is not a
        // listing of objects, but instead contains error information.
        if (http.getLastStatus() != 200) {
            std.debug.print("{s}\n", .{try xml.getXml(alloc)});
            std.debug.print("Failed.\n", .{});
            return;
        }

        // If this is not the final response, then we'll get an XML response that begins
        // like this.  (The IsTruncated child will be "true", and the NextContinuationToken
        // will have a value to be used in the next request.)
        //     <?xml version="1.0" encoding="UTF-8" ?>
        //     <ListBucketResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
        //         <Name>chilkat100</Name>
        //         <Prefix />
        //         <NextContinuationToken>1Mlcx+W9OKsr8cxp3DP6r71wgsTUMj0vqlntWoaJKNbYdrauLdf40LsUdBeSYGFhzbGIHdcf5DSLcEBWbqG+1fW1UcQkUW1V4qgQONAKOwb8y8vOLJAQ8iQ==</NextContinuationToken>
        //         <KeyCount>5</KeyCount>
        //         <MaxKeys>5</MaxKeys>
        //         <IsTruncated>true</IsTruncated>
        //

        // Iterate over the bucket items in this chunk get information for each..
        const num_items = xml.numChildrenHavingTag("Contents");
        std.debug.print("Number of bucket items = {d}\n", .{num_items});

        var i: i32 = 0;
        while (i < num_items) {
            xml.setI(i);

            item_key = try xml.getChildContent(alloc, "Contents[i]|Key");
            item_size_decimal_str = try xml.getChildContent(alloc, "Contents[i]|Size");
            last_mod_timestamp = try xml.getChildContent(alloc, "Contents[i]|LastModified");

            dt.setFromRfc822(last_mod_timestamp) catch {};
            // Get a local date/time.
            const b_local = true;
            dt.toDtObj(b_local, dt_obj);

            std.debug.print("{d}: {s}, {s}, {d}-{d}-{d}:{d}:{d}\n", .{ i, item_key, item_size_decimal_str, dt_obj.getDay(), dt_obj.getMonth(), dt_obj.getYear(), dt_obj.getHour(), dt_obj.getMinute() });

            i = i + 1;
        }

        // Check IsTruncated.
        b_get_more = false;
        if (xml.childContentMatches("IsTruncated", "true", true)) {
            sb_continuation_token.setString(try xml.getChildContent(alloc, "NextContinuationToken")) catch {};
            if (sb_continuation_token.getLength() > 0) {
                b_get_more = true;
            }
        }
    }

    // The output of this example (when tested) was:

    // Response status code = 200
    // Number of bucket items = 5
    // 0: Abc.ics, 1833, 25-5-2011:9:53
    // 1: Corpse Bride film poster.jpg, 53481, 6-9-2016:13:32
    // 2: chiliPepper.gif, 7718, 12-3-2017:12:18
    // 3: chilkatdude.jpg, 35137, 20-5-2011:16:14
    // 4: cloud.search/dfe/indexer/pscc/2016/3/28/id,x-2-15-0-25-87-0.json, 1238, 2-4-2016:12:0
    // Response status code = 200
    // Number of bucket items = 5
    // 0: cloud.search/dfe/indexer/pscc/2016/3/28/idx-2-15-0-25-87-0.json, 1238, 2-4-2016:11:33
    // 1: dude.gif, 6373, 25-5-2011:17:29
    // 2: french.txt, 47, 12-3-2017:12:18
    // 3: hamlet.xml, 279658, 2-5-2016:12:21
    // 4: hamlet_play.xml, 279658, 20-3-2017:8:22
    // Response status code = 200
    // Number of bucket items = 5
    // 0: images/sea_creatures/starfish123.jpg, 6229, 19-1-2017:10:45
    // 1: images/sea_creatures/starfishåäö.jpg, 6229, 19-1-2017:12:7
    // 2: new folder/, 0, 26-11-2014:12:36
    // 3: new_starfish.jpg, 6229, 20-3-2017:8:22
    // 4: pigs.xml, 2804, 20-3-2017:8:22
    // Response status code = 200
    // Number of bucket items = 5
    // 0: somethingBig.zip, 13089458, 26-9-2016:9:29
    // 1: starfish.jpg, 6229, 12-3-2017:12:18
    // 2: starfish/, 0, 10-11-2014:10:7
    // 3: starfish/starfish.jpg, 6229, 10-11-2014:10:8
    // 4: starfish/starfish2.jpg, 6229, 19-11-2014:10:36
    // Response status code = 200
    // Number of bucket items = 5
    // 0: starfish/starfish3.jpg, 6229, 24-11-2014:14:33
    // 1: starfish2.jpg, 5987, 20-4-2012:12:6
    // 2: starfish3.jpg, 5987, 11-4-2012:7:10
    // 3: starfishA.jpg, 6229, 10-5-2016:8:44
    // 4: starfishCust.jpg, 6229, 12-11-2014:18:25
    // Response status code = 200
    // Number of bucket items = 1
    // 0: xyz.ics, 1833, 25-5-2011:8:52
    //
    //
}