Good morning, FIRSTNAME
I am pleased to see that you're performing well under the tutelage of Miss Sháo. Vita tells me that you've found several suspicious pieces of information, whose investigation has resulted in the retrieval of even more useful information! This is great news. Always remember that the ultimate goal of information management is to produce more information.
This is why it's always a good idea to pair fresh consultants with more experienced colleagues. It's a good thing the investigation was upgraded, so you have been blessed with this opportunity to grow. Your partnership with Miss Sháo reminds me of this train:
Just like the engine is responsible for pulling the wagon, so the experienced mentoring of Miss Sháo is pulling you forwards towards greater results.
Speaking of greater experience, I have some good news for you! Since the investigation is now involving potential corruption of the media, it's being upgraded to grade C! Both you and Miss Sháo will henceforth report to Salvinu Manduca. Mr. Manduca is joining us from France, as part of the new synergy initiative, which I'm sure you have heard of. His advanced experience will afford the both of you even more opportunities to learn and advance your careers!
Sandra Silvern
Managing Consultant / Haka Manager


Come on down to Pat's today. In addition to tasty cookies, you can bring home momentos back to your distant relatives who weren't lucky enough to sample Pat's cookies in person. Merchandise like:
Salmon T's -- now only $25!
Cookie Cutters -- starting at $7.50
Salmon hats -- $33
| 1st and Pike | SeaTac Airport | Seattle Center | Capitol Hill | Alki |
|---|---|---|---|---|
| 102 Pike St | 17801 International Blvd, Concourse C | 305 Harrison St | 140 Broadway E | 1702 Alki Ave SW |
| Seattle, WA 98101 | Seattle, WA 98158 | Seattle, WA 98109 | Seattle, WA 98102 | Seattle, WA 98116 |


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-
Human-robot interaction system for non-expert users in convenience stores using behavior trees
Authors:
Pattaraporn Tulathum, Bunyapon Usawalertkamol, Gustavo A Garcia Ricardez, Jun Takamatsu, and Tsukasa Ogasawara, Kenichi Matsumoto
Venue:
IEEE/SICE International Symposium on System Integration (SII), 2022
-
Autonomous service robot for human-aware restock, straightening and disposal tasks in retail automation
Authors:
Gustavo A Garcia Ricardez, Pedro M Uriguen Eljuri, Yuta Kamemura, Shiori Yokota, Noriyuki Kugou, Yoshitatsu Asama, Ziyu Wang, Hikaru Kumamoto, Kotaro Yoshimoto, Wai Y Chan, Tomoki Nagatani, Pattaraporn Tulathum, Bunyapon Usawalertkamol, Lotfi El Hafi, Hiroki Ikeuchi, Masaki Yamamoto, Jun Takamatsu, Tadahiro Taniguchi, and Tsukasa Ogasawara
Venue:
Advanced Robotics, 2022
-
Robot behavior debugger for non-expert users in convenience stores using behavior trees
Authors:
Pattaraporn Tulathum, Bunyapon Usawalertkamol, Gustavo A Garcia Ricardez, Jun Takamatsu, and Tsukasa Ogasawara, Kenichi Matsumoto
Venue:
Advanced Robotics, 2022
-
Toward robot-agnostic home appliance operation: a task execution framework using motion primitives, ontology, and GUI
Authors:
Akishige Yuguchi, Takumi Nakamura, Mayuki Toyoda, Masayuki Yamada, Pattaraporn Tulathum, Maël Aubert, Gustavo A Garcia Ricardez, Jun Takamatsu, and Tsukasa Ogasawara
Venue:
Advanced Robotics, 2022


Drink apple cider vinegar
Food description thats followed after the food title
Unique wood fired pizzas or be tempted by our pasta, antipasto, focaccias, salads and Bruschetta dishes. Relax in the friendly ambience as you enjoy the aromas of the wood ovens or sit al fresco and soak up the Mildura sunshine.
Food description thats followed after the food title
Food description thats followed after the food title
Food description thats followed after the food title
We bring the season's best mix of organic produce and hand- crafted farm products conviniently to your door by growing and partnering with local farms and artisans in your area
- Loo Hudson


Salt you seed
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never share or save this.
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Salt
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Austria hit with heavy snow, flooding and mudslides
Weather system that brought historic flooding to Venice has caused widespread problems across Austria.
Parts of Austria have been dealing with masses of snow, the threat of avalanches and flooding by swelling rivers and lakes.
Firefighters rescued two women buried after a mudslide in Bad Gastein, south of Salzburg, destroyed two homes overnight on Sunday, according to the Austria Presse Agentur (APA) news agency. The women were taken to hospital for their injuries.
In southern Austria, a mudslide killed an 80-year-old man when it hit his home on Monday in Bad Kleinkirchheim. The house was destroyed, Mayor Matthias Krenn told APA.
To the east in Gurktal, in the Carinthia region, the Gurk River rose quickly and threatened residents in 15 buildings close by, leading to a mass evacuation led by local firefighters.
Meanwhile, several train lines were interrupted and about 3,300 houses were without power on Monday in East Tyrol and Carinthia.
Schools were also closed on Monday in East Tyrol because of the threat of avalanches.
More than 30 people were evacuated from their homes in the eastern state of Styria because of the threat of mudslides, according to German news agency, Deutsche Welle.
The widespread heavy snow cut off dozens of villages across southern Austria, with helicopters scouting the nearby mountains for possible avalanches.
Throughout Tuesday and Wednesday, the next weather system will bring another blast of winter across the mountains, with more rain at lower elevations. The risk of flooding and avalanches in the mountains remains high.


reftable
Overview
Problem statement
Some repositories contain a lot of references (e.g. android at 866k, rails at 31k). The existing packed-refs format takes up a lot of space (e.g. 62M), and does not scale with additional references. Lookup of a single reference requires linearly scanning the file.
Atomic pushes modifying multiple references require copying the entire packed-refs file, which can be a considerable amount of data moved (e.g. 62M in, 62M out) for even small transactions (2 refs modified).
Repositories with many loose references occupy a large number of disk
blocks from the local file system, as each reference is its own file
storing 41 bytes (and another file for the corresponding reflog). This
negatively affects the number of inodes available when a large number of
repositories are stored on the same filesystem. Readers can be penalized
due to the larger number of syscalls required to traverse and read the
$GIT_DIR/refs
directory.
Objectives
-
Near constant time lookup for any single reference, even when the repository is cold and not in process or kernel cache.
-
Near constant time verification if an object name is referred to by at least one reference (for allow-tip-sha1-in-want).
-
Efficient enumeration of an entire namespace, such as
refs/tags/
. -
Support atomic push with
O(size_of_update)
operations. -
Combine reflog storage with ref storage for small transactions.
-
Separate reflog storage for base refs and historical logs.
Description
A reftable file is a portable binary file format customized for reference storage. References are sorted, enabling linear scans, binary search lookup, and range scans.
Storage in the file is organized into variable sized blocks. Prefix compression is used within a single block to reduce disk space. Block size and alignment is tunable by the writer.
Performance
Space used, packed-refs vs. reftable:
| repository | packed-refs | reftable | % original | avg ref | avg obj |
|---|---|---|---|---|---|
android |
62.2 M |
36.1 M |
58.0% |
33 bytes |
5 bytes |
rails |
1.8 M |
1.1 M |
57.7% |
29 bytes |
4 bytes |
git |
78.7 K |
48.1 K |
61.0% |
50 bytes |
4 bytes |
git (heads) |
332 b |
269 b |
81.0% |
33 bytes |
0 bytes |
Scan (read 866k refs), by reference name lookup (single ref from 866k refs), and by SHA-1 lookup (refs with that SHA-1, from 866k refs):
| format | cache | scan | by name | by SHA-1 |
|---|---|---|---|---|
packed-refs |
cold |
402 ms |
409,660.1 usec |
412,535.8 usec |
packed-refs |
hot |
6,844.6 usec |
20,110.1 usec |
|
reftable |
cold |
112 ms |
33.9 usec |
323.2 usec |
reftable |
hot |
20.2 usec |
320.8 usec |
Space used for 149,932 log entries for 43,061 refs, reflog vs. reftable:
| format | size | avg entry |
|---|---|---|
$GIT_DIR/logs |
173 M |
1209 bytes |
reftable |
5 M |
37 bytes |
Details
Peeling
References stored in a reftable are peeled, a record for an annotated (or signed) tag records both the tag object, and the object it refers to. This is analogous to storage in the packed-refs format.
Reference name encoding
Reference names are an uninterpreted sequence of bytes that must pass git-check-ref-format(1) as a valid reference name.
Key unicity
Each entry must have a unique key; repeated keys are disallowed.
Network byte order
All multi-byte, fixed width fields are in network byte order.
Varint encoding
Varint encoding is identical to the ofs-delta encoding method used within pack files.
Decoder works such as:
val = buf[ptr] & 0x7f
while (buf[ptr] & 0x80) {
ptr++
val = ((val + 1) << 7) | (buf[ptr] & 0x7f)
}
Ordering
Blocks are lexicographically ordered by their first reference.
Directory/file conflicts
The reftable format accepts both refs/heads/foo
and
refs/heads/foo/bar
as distinct references.
This property is useful for retaining log records in reftable, but may
confuse versions of Git using $GIT_DIR/refs
directory tree to maintain
references. Users of reftable may choose to continue to reject foo
and
foo/bar
type conflicts to prevent problems for peers.
File format
Structure
A reftable file has the following high-level structure:
first_block {
header
first_ref_block
}
ref_block*
ref_index*
obj_block*
obj_index*
log_block*
log_index*
footer
A log-only file omits the ref_block
, ref_index
, obj_block
and
obj_index
sections, containing only the file header and log block:
first_block {
header
}
log_block*
log_index*
footer
in a log-only file the first log block immediately follows the file header, without padding to block alignment.
Block size
The file’s block size is arbitrarily determined by the writer, and does not have to be a power of 2. The block size must be larger than the longest reference name or log entry used in the repository, as references cannot span blocks.
Powers of two that are friendly to the virtual memory system or filesystem (such as 4k or 8k) are recommended. Larger sizes (64k) can yield better compression, with a possible increased cost incurred by readers during access.
The largest block size is 16777215
bytes (15.99 MiB).
Block alignment
Writers may choose to align blocks at multiples of the block size by
including padding
filled with NUL bytes at the end of a block to round
out to the chosen alignment. When alignment is used, writers must
specify the alignment with the file header’s block_size
field.
Block alignment is not required by the file format. Unaligned files must
set block_size = 0
in the file header, and omit padding
. Unaligned
files with more than one ref block must include the ref
index to support fast lookup. Readers must be able to read both aligned
and non-aligned files.
Very small files (e.g. a single ref block) may omit padding
and the ref
index to reduce total file size.
Header (version 1)
A 24-byte header appears at the beginning of the file:
'REFT'
uint8( version_number = 1 )
uint24( block_size )
uint64( min_update_index )
uint64( max_update_index )
Aligned files must specify block_size
to configure readers with the
expected block alignment. Unaligned files must set block_size = 0
.
The min_update_index
and max_update_index
describe bounds for the
update_index
field of all log records in this file. When reftables are
used in a stack for transactions, these
fields can order the files such that the prior file’s
max_update_index + 1
is the next file’s min_update_index
.
Header (version 2)
A 28-byte header appears at the beginning of the file:
'REFT'
uint8( version_number = 2 )
uint24( block_size )
uint64( min_update_index )
uint64( max_update_index )
uint32( hash_id )
The header is identical to version_number=1
, with the 4-byte hash ID
("sha1" for SHA1 and "s256" for SHA-256) append to the header.
For maximum backward compatibility, it is recommended to use version 1 when writing SHA1 reftables.
First ref block
The first ref block shares the same block as the file header, and is 24 bytes smaller than all other blocks in the file. The first block immediately begins after the file header, at position 24.
If the first block is a log block (a log-only file), its block header begins immediately at position 24.
Ref block format
A ref block is written as:
'r'
uint24( block_len )
ref_record+
uint24( restart_offset )+
uint16( restart_count )
padding?
Blocks begin with block_type = 'r'
and a 3-byte block_len
which
encodes the number of bytes in the block up to, but not including the
optional padding
. This is always less than or equal to the file’s
block size. In the first ref block, block_len
includes 24 bytes for
the file header.
The 2-byte restart_count
stores the number of entries in the
restart_offset
list, which must not be empty. Readers can use
restart_count
to binary search between restarts before starting a
linear scan.
Exactly restart_count
3-byte restart_offset
values precedes the
restart_count
. Offsets are relative to the start of the block and
refer to the first byte of any ref_record
whose name has not been
prefix compressed. Entries in the restart_offset
list must be sorted,
ascending. Readers can start linear scans from any of these records.
A variable number of ref_record
fill the middle of the block,
describing reference names and values. The format is described below.
As the first ref block shares the first file block with the file header,
all restart_offset
in the first block are relative to the start of the
file (position 0), and include the file header. This forces the first
restart_offset
to be 28
.
ref record
A ref_record
describes a single reference, storing both the name and
its value(s). Records are formatted as:
varint( prefix_length )
varint( (suffix_length << 3) | value_type )
suffix
varint( update_index_delta )
value?
The prefix_length
field specifies how many leading bytes of the prior
reference record’s name should be copied to obtain this reference’s
name. This must be 0 for the first reference in any block, and also must
be 0 for any ref_record
whose offset is listed in the restart_offset
table at the end of the block.
Recovering a reference name from any ref_record
is a simple concat:
this_name = prior_name[0..prefix_length] + suffix
The suffix_length
value provides the number of bytes available in
suffix
to copy from suffix
to complete the reference name.
The update_index
that last modified the reference can be obtained by
adding update_index_delta
to the min_update_index
from the file
header: min_update_index + update_index_delta
.
The value
follows. Its format is determined by value_type
, one of
the following:
-
0x0
: deletion; no value data (see transactions, below) -
0x1
: one object name; value of the ref -
0x2
: two object names; value of the ref, peeled target -
0x3
: symbolic reference:varint( target_len ) target
Symbolic references use 0x3
, followed by the complete name of the
reference target. No compression is applied to the target name.
Types 0x4..0x7
are reserved for future use.
Ref index
The ref index stores the name of the last reference from every ref block in the file, enabling reduced disk seeks for lookups. Any reference can be found by searching the index, identifying the containing block, and searching within that block.
The index may be organized into a multi-level index, where the 1st level
index block points to additional ref index blocks (2nd level), which may
in turn point to either additional index blocks (e.g. 3rd level) or ref
blocks (leaf level). Disk reads required to access a ref go up with
higher index levels. Multi-level indexes may be required to ensure no
single index block exceeds the file format’s max block size of
16777215
bytes (15.99 MiB). To achieve constant O(1) disk seeks for
lookups the index must be a single level, which is permitted to exceed
the file’s configured block size, but not the format’s max block size of
15.99 MiB.
If present, the ref index block(s) appears after the last ref block.
If there are at least 4 ref blocks, a ref index block should be written to improve lookup times. Cold reads using the index require 2 disk reads (read index, read block), and binary searching < 4 blocks also requires ⇐ 2 reads. Omitting the index block from smaller files saves space.
If the file is unaligned and contains more than one ref block, the ref index must be written.
Index block format:
'i'
uint24( block_len )
index_record+
uint24( restart_offset )+
uint16( restart_count )
padding?
The index blocks begin with block_type = 'i'
and a 3-byte block_len
which encodes the number of bytes in the block, up to but not including
the optional padding
.
The restart_offset
and restart_count
fields are identical in format,
meaning and usage as in ref blocks.
To reduce the number of reads required for random access in very large files the index block may be larger than other blocks. However, readers must hold the entire index in memory to benefit from this, so it’s a time-space tradeoff in both file size and reader memory.
Increasing the file’s block size decreases the index size. Alternatively a multi-level index may be used, keeping index blocks within the file’s block size, but increasing the number of blocks that need to be accessed.
index record
An index record describes the last entry in another block. Index records are written as:
varint( prefix_length )
varint( (suffix_length << 3) | 0 )
suffix
varint( block_position )
Index records use prefix compression exactly like ref_record
.
Index records store block_position
after the suffix, specifying the
absolute position in bytes (from the start of the file) of the block
that ends with this reference. Readers can seek to block_position
to
begin reading the block header.
Readers must examine the block header at block_position
to determine
if the next block is another level index block, or the leaf-level ref
block.
Reading the index
Readers loading the ref index must first read the footer (below) to
obtain ref_index_position
. If not present, the position will be 0. The
ref_index_position
is for the 1st level root of the ref index.
Obj block format
Object blocks are optional. Writers may choose to omit object blocks, especially if readers will not use the object name to ref mapping.
Object blocks use unique, abbreviated 2-32 object name keys, mapping to
ref blocks containing references pointing to that object directly, or as
the peeled value of an annotated tag. Like ref blocks, object blocks use
the file’s standard block size. The abbrevation length is available in
the footer as obj_id_len
.
To save space in small files, object blocks may be omitted if the ref index is not present, as brute force search will only need to read a few ref blocks. When missing, readers should brute force a linear search of all references to lookup by object name.
An object block is written as:
'o'
uint24( block_len )
obj_record+
uint24( restart_offset )+
uint16( restart_count )
padding?
Fields are identical to ref block. Binary search using the restart table works the same as in reference blocks.
Because object names are abbreviated by writers to the shortest unique abbreviation within the reftable, obj key lengths have a variable length. Their length must be at least 2 bytes. Readers must compare only for common prefix match within an obj block or obj index.
obj record
An obj_record
describes a single object abbreviation, and the blocks
containing references using that unique abbreviation:
varint( prefix_length )
varint( (suffix_length << 3) | cnt_3 )
suffix
varint( cnt_large )?
varint( position_delta )*
Like in reference blocks, abbreviations are prefix compressed within an
obj block. On large reftables with many unique objects, higher block
sizes (64k), and higher restart interval (128), a prefix_length
of 2
or 3 and suffix_length
of 3 may be common in obj records (unique
abbreviation of 5-6 raw bytes, 10-12 hex digits).
Each record contains position_count
number of positions for matching
ref blocks. For 1-7 positions the count is stored in cnt_3
. When
cnt_3 = 0
the actual count follows in a varint, cnt_large
.
The use of cnt_3
bets most objects are pointed to by only a single
reference, some may be pointed to by a couple of references, and very
few (if any) are pointed to by more than 7 references.
A special case exists when cnt_3 = 0
and cnt_large = 0
: there are no
position_delta
, but at least one reference starts with this
abbreviation. A reader that needs exact reference names must scan all
references to find which specific references have the desired object.
Writers should use this format when the position_delta
list would have
overflowed the file’s block size due to a high number of references
pointing to the same object.
The first position_delta
is the position from the start of the file.
Additional position_delta
entries are sorted ascending and relative to
the prior entry, e.g. a reader would perform:
pos = position_delta[0]
prior = pos
for (j = 1; j < position_count; j++) {
pos = prior + position_delta[j]
prior = pos
}
With a position in hand, a reader must linearly scan the ref block,
starting from the first ref_record
, testing each reference’s object names
(for value_type = 0x1
or 0x2
) for full equality. Faster searching by
object name within a single ref block is not supported by the reftable format.
Smaller block sizes reduce the number of candidates this step must
consider.
Obj index
The obj index stores the abbreviation from the last entry for every obj block in the file, enabling reduced disk seeks for all lookups. It is formatted exactly the same as the ref index, but refers to obj blocks.
The obj index should be present if obj blocks are present, as obj blocks should only be written in larger files.
Readers loading the obj index must first read the footer (below) to
obtain obj_index_position
. If not present, the position will be 0.
Log block format
Unlike ref and obj blocks, log blocks are always unaligned.
Log blocks are variable in size, and do not match the block_size
specified in the file header or footer. Writers should choose an
appropriate buffer size to prepare a log block for deflation, such as
2 * block_size
.
A log block is written as:
'g'
uint24( block_len )
zlib_deflate {
log_record+
uint24( restart_offset )+
uint16( restart_count )
}
Log blocks look similar to ref blocks, except block_type = 'g'
.
The 4-byte block header is followed by the deflated block contents using
zlib deflate. The block_len
in the header is the inflated size
(including 4-byte block header), and should be used by readers to
preallocate the inflation output buffer. A log block’s block_len
may
exceed the file’s block size.
Offsets within the log block (e.g. restart_offset
) still include the
4-byte header. Readers may prefer prefixing the inflation output buffer
with the 4-byte header.
Within the deflate container, a variable number of log_record
describe
reference changes. The log record format is described below. See ref
block format (above) for a description of restart_offset
and
restart_count
.
Because log blocks have no alignment or padding between blocks, readers must keep track of the bytes consumed by the inflater to know where the next log block begins.
log record
Log record keys are structured as:
ref_name '\0' reverse_int64( update_index )
where update_index
is the unique transaction identifier. The
update_index
field must be unique within the scope of a ref_name
.
See the update transactions section below for further details.
The reverse_int64
function inverses the value so lexicographical
ordering the network byte order encoding sorts the more recent records
with higher update_index
values first:
reverse_int64(int64 t) {
return 0xffffffffffffffff - t;
}
Log records have a similar starting structure to ref and index records, utilizing the same prefix compression scheme applied to the log record key described above.
varint( prefix_length )
varint( (suffix_length << 3) | log_type )
suffix
log_data {
old_id
new_id
varint( name_length ) name
varint( email_length ) email
varint( time_seconds )
sint16( tz_offset )
varint( message_length ) message
}?
Log record entries use log_type
to indicate what follows:
-
0x0
: deletion; no log data. -
0x1
: standard git reflog data usinglog_data
above.
The log_type = 0x0
is mostly useful for git stash drop
, removing an
entry from the reflog of refs/stash
in a transaction file (below),
without needing to rewrite larger files. Readers reading a stack of
reflogs must treat this as a deletion.
For log_type = 0x1
, the log_data
section follows
git-update-ref(1) logging and includes:
-
two object names (old id, new id)
-
varint string of committer’s name
-
varint string of committer’s email
-
varint time in seconds since epoch (Jan 1, 1970)
-
2-byte timezone offset in minutes (signed)
-
varint string of message
tz_offset
is the absolute number of minutes from GMT the committer was
at the time of the update. For example GMT-0800
is encoded in reftable
as sint16(-480)
and GMT+0230
is sint16(150)
.
The committer email does not contain <
or >
, it’s the value normally
found between the <>
in a git commit object header.
The message_length
may be 0, in which case there was no message
supplied for the update.
Contrary to traditional reflog (which is a file), renames are encoded as a combination of ref deletion and ref creation. A deletion is a log record with a zero new_id, and a creation is a log record with a zero old_id.
Reading the log
Readers accessing the log must first read the footer (below) to
determine the log_position
. The first block of the log begins at
log_position
bytes since the start of the file. The log_position
is
not block aligned.
Importing logs
When importing from $GIT_DIR/logs
writers should globally order all
log records roughly by timestamp while preserving file order, and assign
unique, increasing update_index
values for each log line. Newer log
records get higher update_index
values.
Although an import may write only a single reftable file, the reftable
file must span many unique update_index
, as each log line requires its
own update_index
to preserve semantics.
Log index
The log index stores the log key
(refname \0 reverse_int64(update_index)
) for the last log record of
every log block in the file, supporting bounded-time lookup.
A log index block must be written if 2 or more log blocks are written to the file. If present, the log index appears after the last log block. There is no padding used to align the log index to block alignment.
Log index format is identical to ref index, except the keys are 9 bytes
longer to include '\0'
and the 8-byte reverse_int64(update_index)
.
Records use block_position
to refer to the start of a log block.
Reading the index
Readers loading the log index must first read the footer (below) to
obtain log_index_position
. If not present, the position will be 0.
Footer
After the last block of the file, a file footer is written. It begins like the file header, but is extended with additional data.
HEADER
uint64( ref_index_position )
uint64( (obj_position << 5) | obj_id_len )
uint64( obj_index_position )
uint64( log_position )
uint64( log_index_position )
uint32( CRC-32 of above )
If a section is missing (e.g. ref index) the corresponding position
field (e.g. ref_index_position
) will be 0.
-
obj_position
: byte position for the first obj block. -
obj_id_len
: number of bytes used to abbreviate object names in obj blocks. -
log_position
: byte position for the first log block. -
ref_index_position
: byte position for the start of the ref index. -
obj_index_position
: byte position for the start of the obj index. -
log_index_position
: byte position for the start of the log index.
The size of the footer is 68 bytes for version 1, and 72 bytes for version 2.
Reading the footer
Readers must first read the file start to determine the version
number. Then they seek to file_length - FOOTER_LENGTH
to access the
footer. A trusted external source (such as stat(2)
) is necessary to
obtain file_length
. When reading the footer, readers must verify:
-
4-byte magic is correct
-
1-byte version number is recognized
-
4-byte CRC-32 matches the other 64 bytes (including magic, and version)
Once verified, the other fields of the footer can be accessed.
Empty tables
A reftable may be empty. In this case, the file starts with a header and is immediately followed by a footer.
Binary search
Binary search within a block is supported by the restart_offset
fields
at the end of the block. Readers can binary search through the restart
table to locate between which two restart points the sought reference or
key should appear.
Each record identified by a restart_offset
stores the complete key in
the suffix
field of the record, making the compare operation during
binary search straightforward.
Once a restart point lexicographically before the sought reference has been identified, readers can linearly scan through the following record entries to locate the sought record, terminating if the current record sorts after (and therefore the sought key is not present).
Restart point selection
Writers determine the restart points at file creation. The process is arbitrary, but every 16 or 64 records is recommended. Every 16 may be more suitable for smaller block sizes (4k or 8k), every 64 for larger block sizes (64k).
More frequent restart points reduces prefix compression and increases space consumed by the restart table, both of which increase file size.
Less frequent restart points makes prefix compression more effective, decreasing overall file size, with increased penalties for readers walking through more records after the binary search step.
A maximum of 65535
restart points per block is supported.
Considerations
Lightweight refs dominate
The reftable format assumes the vast majority of references are single
object names valued with common prefixes, such as Gerrit Code Review’s
refs/changes/
namespace, GitHub’s refs/pulls/
namespace, or many
lightweight tags in the refs/tags/
namespace.
Annotated tags storing the peeled object cost an additional object name per reference.
Low overhead
A reftable with very few references (e.g. git.git with 5 heads) is 269 bytes for reftable, vs. 332 bytes for packed-refs. This supports reftable scaling down for transaction logs (below).
Block size
For a Gerrit Code Review type repository with many change refs, larger block sizes (64 KiB) and less frequent restart points (every 64) yield better compression due to more references within the block compressing against the prior reference.
Larger block sizes reduce the index size, as the reftable will require fewer blocks to store the same number of references.
Minimal disk seeks
Assuming the index block has been loaded into memory, binary searching for any single reference requires exactly 1 disk seek to load the containing block.
Scans and lookups dominate
Scanning all references and lookup by name (or namespace such as
refs/heads/
) are the most common activities performed on repositories.
Object names are stored directly with references to optimize this use case.
Logs are infrequently read
Logs are infrequently accessed, but can be large. Deflating log blocks saves disk space, with some increased penalty at read time.
Logs are stored in an isolated section from refs, reducing the burden on reference readers that want to ignore logs. Further, historical logs can be isolated into log-only files.
Logs are read backwards
Logs are frequently accessed backwards (most recent N records for master
to answer master@{4}
), so log records are grouped by reference, and
sorted descending by update index.
Repository format
Version 1
A repository must set its $GIT_DIR/config
to configure reftable:
[core]
repositoryformatversion = 1
[extensions]
refStorage = reftable
Layout
A collection of reftable files are stored in the $GIT_DIR/reftable/
directory:
00000001-00000001.log
00000002-00000002.ref
00000003-00000003.ref
where reftable files are named by a unique name such as produced by the
function ${min_update_index}-${max_update_index}.ref
.
Log-only files use the .log
extension, while ref-only and mixed ref
and log files use .ref
. extension.
The stack ordering file is $GIT_DIR/reftable/tables.list
and lists the
current files, one per line, in order, from oldest (base) to newest
(most recent):
$ cat .git/reftable/tables.list
00000001-00000001.log
00000002-00000002.ref
00000003-00000003.ref
Readers must read $GIT_DIR/reftable/tables.list
to determine which
files are relevant right now, and search through the stack in reverse
order (last reftable is examined first).
Reftable files not listed in tables.list
may be new (and about to be
added to the stack by the active writer), or ancient and ready to be
pruned.
Backward compatibility
Older clients should continue to recognize the directory as a git repository so they don’t look for an enclosing repository in parent directories. To this end, a reftable-enabled repository must contain the following dummy files
-
.git/HEAD
, a regular file containingref: refs/heads/.invalid
. -
.git/refs/
, a directory -
.git/refs/heads
, a regular file
Readers
Readers can obtain a consistent snapshot of the reference space by following:
-
Open and read the
tables.list
file. -
Open each of the reftable files that it mentions.
-
If any of the files is missing, goto 1.
-
Read from the now-open files as long as necessary.
Update transactions
Although reftables are immutable, mutations are supported by writing a new reftable and atomically appending it to the stack:
-
Acquire
tables.list.lock
. -
Read
tables.list
to determine current reftables. -
Select
update_index
to be most recent file’smax_update_index + 1
. -
Prepare temp reftable
tmp_XXXXXX
, including log entries. -
Rename
tmp_XXXXXX
to${update_index}-${update_index}.ref
. -
Copy
tables.list
totables.list.lock
, appending file from (5). -
Rename
tables.list.lock
totables.list
.
During step 4 the new file’s min_update_index
and max_update_index
are both set to the update_index
selected by step 3. All log records
for the transaction use the same update_index
in their keys. This
enables later correlation of which references were updated by the same
transaction.
Because a single tables.list.lock
file is used to manage locking, the
repository is single-threaded for writers. Writers may have to busy-spin
(with backoff) around creating tables.list.lock
, for up to an
acceptable wait period, aborting if the repository is too busy to
mutate. Application servers wrapped around repositories (e.g. Gerrit
Code Review) can layer their own lock/wait queue to improve fairness to
writers.
Reference deletions
Deletion of any reference can be explicitly stored by setting the type
to 0x0
and omitting the value
field of the ref_record
. This serves
as a tombstone, overriding any assertions about the existence of the
reference from earlier files in the stack.
Compaction
A partial stack of reftables can be compacted by merging references using a straightforward merge join across reftables, selecting the most recent value for output, and omitting deleted references that do not appear in remaining, lower reftables.
A compacted reftable should set its ‘min_update_index` to the smallest
of the input files’ min_update_index
, and its max_update_index
likewise to the largest input max_update_index
.
For sake of illustration, assume the stack currently consists of reftable files (from oldest to newest): A, B, C, and D. The compactor is going to compact B and C, leaving A and D alone.
-
Obtain lock
tables.list.lock
and read thetables.list
file. -
Obtain locks
B.lock
andC.lock
. Ownership of these locks prevents other processes from trying to compact these files. -
Release
tables.list.lock
. -
Compact
B
andC
into a temp file${min_update_index}-${max_update_index}_XXXXXX
. -
Reacquire lock
tables.list.lock
. -
Verify that
B
andC
are still in the stack, in that order. This should always be the case, assuming that other processes are adhering to the locking protocol. -
Rename
${min_update_index}-${max_update_index}_XXXXXX
to${min_update_index}-${max_update_index}.ref
. -
Write the new stack to
tables.list.lock
, replacingB
andC
with the file from (4). -
Rename
tables.list.lock
totables.list
. -
Delete
B
andC
, perhaps after a short sleep to avoid forcing readers to backtrack.
This strategy permits compactions to proceed independently of updates.
Each reftable (compacted or not) is uniquely identified by its name, so open reftables can be cached by their name.
Alternatives considered
bzip packed-refs
bzip2
can significantly shrink a large packed-refs file (e.g. 62 MiB
compresses to 23 MiB, 37%). However the bzip format does not support
random access to a single reference. Readers must inflate and discard
while performing a linear scan.
Breaking packed-refs into chunks (individually compressing each chunk) would reduce the amount of data a reader must inflate, but still leaves the problem of indexing chunks to support readers efficiently locating the correct chunk.
Given the compression achieved by reftable’s encoding, it does not seem necessary to add the complexity of bzip/gzip/zlib.
Michael Haggerty’s alternate format
Michael Haggerty proposed an alternate format to reftable on the Git mailing list. This format uses smaller chunks, without the restart table, and avoids block alignment with padding. Reflog entries immediately follow each ref, and are thus interleaved between refs.
Performance testing indicates reftable is faster for lookups (51% faster, 11.2 usec vs. 5.4 usec), although reftable produces a slightly larger file (+ ~3.2%, 28.3M vs 29.2M):
| format | size | seek cold | seek hot |
|---|---|---|---|
mh-alt |
28.3 M |
23.4 usec |
11.2 usec |
reftable |
29.2 M |
19.9 usec |
5.4 usec |
JGit Ketch RefTree
JGit Ketch proposed RefTree, an encoding of references inside Git tree objects stored as part of the repository’s object database.
The RefTree format adds additional load on the object database storage layer (more loose objects, more objects in packs), and relies heavily on the packer’s delta compression to save space. Namespaces which are flat (e.g. thousands of tags in refs/tags) initially create very large loose objects, and so RefTree does not address the problem of copying many references to modify a handful.
Flat namespaces are not efficiently searchable in RefTree, as tree
objects in canonical formatting cannot be binary searched. This fails
the need to handle a large number of references in a single namespace,
such as GitHub’s refs/pulls
, or a project with many tags.
LMDB
David Turner proposed using LMDB, as LMDB is lightweight (64k of runtime code) and GPL-compatible license.
A downside of LMDB is its reliance on a single C implementation. This makes embedding inside JGit (a popular reimplementation of Git) difficult, and hoisting onto virtual storage (for JGit DFS) virtually impossible.
A common format that can be supported by all major Git implementations (git-core, JGit, libgit2) is strongly preferred.


This website markets our clothes printed Ikalanga classics!
Find Out MoreNtupo Wear is a clothing company that was formed back in 2009 by Mbaki Selolwane with the hopes of selling kalanga classic wear, all the clothes branded kalanga words. The company wexpanded to sell more stuff like camp chairs, bottles and other merchandise still branded. Ntupo is owned by a young motswana and it has a goal of one day growing to hire other young people.
Get Started!We provide tshirts long and short sleeves, vests and shirts for all mean, woman and children.
We have hoodies available in different colors for all man, woman and children!
Ntupo Wear offers caps and bucket hats for both man and children.
Camp Chaits printrd the label are available for buying!
Ntupo Wear is available anytime to supply the merchandise anywhere in the country, we aim to sell gear to all parts of Botswana, contact us here for more information on to buy, or to get a qoutation!
+267 72 143 811


This project was aimed to visualize the weather of 500+ cities across the world of varying distance from the equator. To accomplish this, we have use a the OpenWeatherMap API, Python libraries as pandas and Matplotlib.
Once data received from API, we have used Matplotlib to plot various aspects of the weather vs. latitude. It includes temperature, cloudiness, wind speed and humidity. This site provides the source data and visualizations created as part of the analysis, as well as explanation and descriptions of any trends and correlations witnessed.


mentioned
by Kevin Reiss at 2020-03-30 13:22:18.subscribed
by Kevin Reiss at 2020-03-30 13:22:18.referenced
by Kevin Reiss at 2020-03-30 13:48:15.merged
by Kevin Reiss at 2020-03-30 13:48:15.closed
by Kevin Reiss at 2020-03-30 13:48:15.head_ref_deleted
by Kevin Reiss at 2020-03-30 13:48:20.referenced
by Kevin Reiss at 2020-03-30 15:27:27.merged
by Kevin Reiss at 2020-03-30 15:27:28.closed
by Kevin Reiss at 2020-03-30 15:27:28.head_ref_deleted
by Kevin Reiss at 2020-03-30 15:27:31.head_ref_force_pushed
by None at 2020-03-30 15:28:26.(Sorry. Should I be attaching folks to these jobs? 😳 )
@smallfind I just moved it over. You should be able to do this in the future by editing the record and changing the "Source Metadata Identifier"
assigned
by Trey Pendragon at 2020-03-30 21:03:20.mentioned
by David Platt at 2020-03-30 22:43:46.subscribed
by David Platt at 2020-03-30 22:43:46.closed
by Trey Pendragon at 2020-03-30 22:45:55.closed
by Trey Pendragon at 2020-03-30 22:47:33.closed
by Trey Pendragon at 2020-03-30 22:49:00.closed
by Trey Pendragon at 2020-03-30 22:51:49.@smallfind Neither of the volumes in that first set appear to be struct-mapped. Are you sure?
mentioned
by David Platt at 2020-03-30 22:54:07.subscribed
by David Platt at 2020-03-30 22:54:07.closed
by Trey Pendragon at 2020-03-30 22:57:49.closed
by Trey Pendragon at 2020-03-30 23:00:51.This used to work. I believe it has something to do with the watch
method that was added recently here.
labeled
by Esmé Cowles at 2020-03-30 15:23:59.labeled
by Esmé Cowles at 2020-03-30 20:06:04.labeled
by Esmé Cowles at 2020-03-30 20:06:04.labeled
by Esmé Cowles at 2020-03-30 20:06:23.ready_for_review
by Trey Pendragon at 2020-03-31 00:27:54.deployed
by Trey Pendragon at 2020-03-31 00:55:20.assigned
by None at 2020-03-30 17:30:11.renamed
by None at 2020-03-30 17:57:16.head_ref_force_pushed
by None at 2020-03-30 14:43:32.referenced
by Francis Kayiwa at 2020-03-30 17:45:10.merged
by Francis Kayiwa at 2020-03-30 17:45:11.closed
by Francis Kayiwa at 2020-03-30 17:45:11.head_ref_deleted
by Francis Kayiwa at 2020-03-30 17:45:14.can we use consul
head_ref_force_pushed
by Francis Kayiwa at 2020-03-30 18:31:09.referenced
by None at 2020-03-30 19:31:37.merged
by None at 2020-03-30 19:31:37.closed
by None at 2020-03-30 19:31:37.head_ref_deleted
by None at 2020-03-30 19:31:41.referenced
by Kevin Reiss at 2020-03-30 20:38:22.merged
by Kevin Reiss at 2020-03-30 20:38:22.closed
by Kevin Reiss at 2020-03-30 20:38:22.head_ref_deleted
by Kevin Reiss at 2020-03-30 20:38:26.renamed
by Trey Pendragon at 2020-03-30 22:04:41.head_ref_force_pushed
by Trey Pendragon at 2020-03-30 22:06:06.referenced
by Eliot Jordan at 2020-03-30 22:31:44.merged
by Eliot Jordan at 2020-03-30 22:31:44.closed
by Eliot Jordan at 2020-03-30 22:31:44.head_ref_deleted
by Eliot Jordan at 2020-03-30 22:31:47.referenced
by Kevin Reiss at 2020-03-31 01:36:10.merged
by Kevin Reiss at 2020-03-31 01:36:10.closed
by Kevin Reiss at 2020-03-31 01:36:10.head_ref_deleted
by Kevin Reiss at 2020-03-31 01:36:18.Provisioned with ansible (follow-up PR to come) and deployed the app. I did some cleanup:
/etc/systemd/system/plantain-workers.service
Testing included:
sudo passenger-status
to ensure the app was running from the new locationclosed
by None at 2020-03-30 14:27:44.referenced
by None at 2020-03-30 14:27:46.deployed
by Trey Pendragon at 2020-03-30 13:27:16.referenced
by None at 2020-03-30 14:27:44.merged
by None at 2020-03-30 14:27:44.closed
by None at 2020-03-30 14:27:45.head_ref_deleted
by None at 2020-03-30 14:27:48.referenced
by James R. Griffin III at 2020-03-30 14:43:20.merged
by James R. Griffin III at 2020-03-30 14:43:20.closed
by James R. Griffin III at 2020-03-30 14:43:20.head_ref_deleted
by James R. Griffin III at 2020-03-30 14:43:23.@apferrar What does this issue mean? What is the context?
@sdellis Hi Shaun- this relates to something the previous WG had discussed. This may be more of a design-related issue than one related to functionality(?); but as with the current site, we would like to privilege description over container information. So, rather than having description display as such: "Folder 2: Letter from Abraham Lincoln to James Gordon Bennett, 1865," where the container information is displayed first, we'd like the order to be reversed. (This is the collection I'm using as an example: https://pulfalight-staging.princeton.edu/catalog/C0094.) This method also makes sense since, as you know, the description of an intellectual grouping can be associated with several containers.
mentioned
by Amanda Ferrara at 2020-03-30 16:29:27.subscribed
by Amanda Ferrara at 2020-03-30 16:29:27.mentioned
by Shaun Ellis at 2020-03-30 18:11:32.subscribed
by Shaun Ellis at 2020-03-30 18:11:33.More attempts to improve caching lead to the following errors with solr_wrapper
:
org.apache.solr.common.SolrException: this IndexWriter is closed
...which is propagated from:
jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
labeled
by James R. Griffin III at 2020-03-30 18:32:38.milestoned
by James R. Griffin III at 2020-03-30 18:32:38.closed
by Trey Pendragon at 2020-03-30 19:02:35.closed
by Trey Pendragon at 2020-03-30 19:02:42.The following item should have the Universal Viewer embedded:
labeled
by James R. Griffin III at 2020-03-30 19:06:43.milestoned
by James R. Griffin III at 2020-03-30 19:06:43.labeled
by James R. Griffin III at 2020-03-30 19:10:42.milestoned
by James R. Griffin III at 2020-03-30 19:10:42.labeled
by James R. Griffin III at 2020-03-30 19:13:08.milestoned
by James R. Griffin III at 2020-03-30 19:13:08.mentioned
by Trey Pendragon at 2020-03-30 19:13:08.subscribed
by Trey Pendragon at 2020-03-30 19:13:08.labeled
by James R. Griffin III at 2020-03-30 19:15:01.milestoned
by James R. Griffin III at 2020-03-30 19:15:01.Might it be possible to more closely follow the design for the collapsible finding aid view for PULFA 2.0?
Perhaps in the center of the page, there can be an expand/collapse interface component for viewing collection and component descriptions.
labeled
by James R. Griffin III at 2020-03-30 19:22:21.milestoned
by James R. Griffin III at 2020-03-30 19:22:21.This was initiated during the planning meeting held on 03/30, where it was determined that the "Collection Context" interface needed to be redesigned to more closely resemble the "table of contents" style design offered on PULFA 2.0.
It was also found that there may be inconsistencies between the community wireframes and the ArcLight MVP. It might be helpful to pose some questions with those who were involved in the production of the community wireframes.
From the ArchiveSpace PUI, there is a "table of contents" style interface component.
labeled
by James R. Griffin III at 2020-03-30 19:16:52.milestoned
by James R. Griffin III at 2020-03-30 19:16:53.labeled
by James R. Griffin III at 2020-03-30 19:32:30.renamed
by James R. Griffin III at 2020-03-30 19:35:19.labeled
by James R. Griffin III at 2020-03-30 19:38:35.milestoned
by James R. Griffin III at 2020-03-30 19:38:35.labeled
by James R. Griffin III at 2020-03-30 19:40:07.labeled
by James R. Griffin III at 2020-03-30 19:40:07.milestoned
by James R. Griffin III at 2020-03-30 19:40:07.closed
by James R. Griffin III at 2020-03-30 19:44:06.closed
by James R. Griffin III at 2020-03-30 19:44:53.We could avoid any warning with a better representation of the data in the facet. The Date Range facet in PulfaLight should be consistent with the Date Range facet in OrangeLight, which gives a histogram of date ranges in the results and a link to "undated" material that can't be represented. See screen shot (although I don't know why it spans beyond the current year).
Invalid date years should not be rendered in the slider.
There are three possible cases which cannot be parsed into datestamps:
Facets will not directly map to the text which is rendered in the field for the record in all cases.
closed
by James R. Griffin III at 2020-03-30 19:45:50.reopened
by James R. Griffin III at 2020-03-30 19:45:58.renamed
by James R. Griffin III at 2020-03-30 19:46:25.We can use the original wireframes for the Collection Context. See page 10, Component Details. For some reason, Stanford did not design this in accordance with the recommendations of their own UX team, but the original wireframe is closer to where we want to be.
I think the problem with Collection Context is not the label, but that it's somewhat redundant with the hierarchy represented above it. If the "Collection Context" heading is still an issue after matching the original wireframe, we can look into changing the heading then.
Closed in favor of #206
closed
by James R. Griffin III at 2020-03-30 19:50:53.It's unclear to me why this has the "wireframe" and "visual design" labels. This is a fairly straightforward request to allow for searching for containers within a collection.
However, rather than using underscores as suggested above (C1234Box12Folder2), I would use more common search syntax of quoting strings with spaces".
So, if one searches for C1234 "Box 12" "Folder 2"
the only search result would be the component in C1234 that has that container and sub-container.
unlabeled
by James R. Griffin III at 2020-03-30 19:51:28.unlabeled
by James R. Griffin III at 2020-03-30 19:51:28.Resolved by #195
closed
by James R. Griffin III at 2020-03-30 19:53:32.This work shall now integrate with the API for Aeon installations rather than submit HTML form requests.
This was tested and confirmed as functioning as required.
closed
by James R. Griffin III at 2020-03-30 19:56:42.Given that a LUX component is being actively developed to produce a preferred solution for request management at the collection level (or for multiple components across collections), this has been deprecated in favor of just disabling the bookmark feature outright.
closed
by James R. Griffin III at 2020-03-30 19:58:25.@hackmastera I'm not seeing child objects in your screenshots, but rather a redundancy with the current object's digitized content. Do you have examples of the digitized content for the child objects? (By objects
, are we talking about components? Or are these objects with parent-child relationships in Figgy?)
A slightly related note: I also noticed essentially a "table of contents" that should probably be in the viewer for better UX/Usability, but is instead described in the EAD. Notice that his has children components here in PULFA:
https://findingaids.princeton.edu/collections/C0744.03/c0002
But not here in pulfalight: https://pulfalight-staging.princeton.edu/catalog/C0744-03C0744-03_c0002
@sdellis The table of contents bug has been ticketed as #163
The child object scenario happens when you look at the "online content" tab for a collection. Here's a screenshot:
mentioned
by None at 2020-03-30 18:31:48.subscribed
by None at 2020-03-30 18:31:48.mentioned
by Shaun Ellis at 2020-03-30 20:10:36.subscribed
by Shaun Ellis at 2020-03-30 20:10:36.@apferrar Is there a screen shot for this, or example we can see from the current site? This applies to any containers, not just folders, correct?
@sdellis Yes, Shaun; this would apply to any container. One example is here: https://pulfalight-staging.princeton.edu/catalog/C1352. Navigate to the component for "Reeve, Tapping, 1770-1810." The request is for all of the associated folders (the folder range) to display (after the unittitle) as well as the extent info, which in this case would be 5 folders.
mentioned
by Amanda Ferrara at 2020-03-30 18:10:21.subscribed
by Amanda Ferrara at 2020-03-30 18:10:21.mentioned
by Shaun Ellis at 2020-03-30 20:11:14.subscribed
by Shaun Ellis at 2020-03-30 20:11:14.review_requested
by Christina Chortaria at 2020-03-30 17:29:44.referenced
by Christina Chortaria at 2020-03-30 17:45:23.merged
by Christina Chortaria at 2020-03-30 17:45:23.closed
by Christina Chortaria at 2020-03-30 17:45:23.review_requested
by Christina Chortaria at 2020-03-30 18:17:49.referenced
by Christina Chortaria at 2020-03-30 18:38:15.merged
by Christina Chortaria at 2020-03-30 18:38:15.closed
by Christina Chortaria at 2020-03-30 18:38:15.labeled
by None at 2020-03-30 18:41:49.unassigned
by Eliot Jordan at 2020-03-30 18:43:29.bundle exec rake ci will fail with ruby 2.6.5: ``` Bundler could not find compatible versions for gem "railties": In snapshot (Gemfile.lock): railties (= 5.1.7)
In Gemfile: rails (~> 5.1.7) was resolved to 5.1.7, which depends on railties (= 5.1.7)
sass-rails (~> 5.0) was resolved to 5.1.0, which depends on
railties (>= 5.2.0)
Running bundle update
will rebuild your snapshot from scratch, using only
the gems in your Gemfile, which may resolve the conflict.
```
renamed
by Christina Chortaria at 2020-03-30 19:13:27.assigned
by Christina Chortaria at 2020-03-30 19:13:41.assigned
by None at 2020-03-30 19:54:48.referenced
by Christina Chortaria at 2020-03-30 19:55:15.merged
by Christina Chortaria at 2020-03-30 19:55:15.closed
by Christina Chortaria at 2020-03-30 19:55:15.assigned
by None at 2020-03-30 19:35:42.closed
by Christina Chortaria at 2020-03-30 19:55:15.@carolyncole there is a conflict
mentioned
by None at 2020-03-30 20:15:40.subscribed
by None at 2020-03-30 20:15:40.review_requested
by Christina Chortaria at 2020-03-30 20:15:48.assigned
by Christina Chortaria at 2020-03-30 20:38:16.referenced
by Trey Pendragon at 2020-03-30 22:02:01.merged
by Trey Pendragon at 2020-03-30 22:02:01.closed
by Trey Pendragon at 2020-03-30 22:02:01.


Exit Codesedit
Exit codes will indicate success or failure.
-
0
— Success -
1
— Failure -
-1
- Exception raised that does not result in a1
exit code.
Exit codes will indicate success or failure.
0
— Success
1
— Failure
-1
- Exception raised that does not result in a 1
exit code.


--- layout: post title: How to Create an Apple ID w/o credit card information within iTunes permalink: how-to-create-an-apple-id-wo-credit-card-information-within-itunes/ date: 2012-03-31 10:12:11.000000000 +08:00 categories: - apple - featured tags: - account - apple - credit card - id status: publish type: post published: true meta: _yoast_wpseo_canonical: '' _yoast_wpseo_redirect: '' _yoast_wpseo_focuskw: '' _yoast_wpseo_title: '' _yoast_wpseo_metadesc: '' _yoast_wpseo_meta-robots-noindex: '0' _yoast_wpseo_meta-robots-nofollow: '0' _edit_last: '2' OGP: a:20:{s:5:"title";s:0:"";s:4:"type";s:0:"";s:5:"image";s:0:"";s:11:"description";s:0:"";s:9:"fb:admins";s:0:"";s:9:"fb:app_id";s:0:"";s:14:"street-address";s:0:"";s:4:"city";s:0:"";s:11:"postal-code";s:0:"";s:12:"country-name";s:0:"";s:5:"email";s:0:"";s:12:"phone_number";s:0:"";s:10:"fax_number";s:0:"";s:5:"video";s:0:"";s:10:"videowidth";s:0:"";s:11:"videoheight";s:0:"";s:9:"videotype";s:0:"";s:6:"locale";s:0:"";s:18:"locale-alternative";s:0:"";s:3:"url";s:0:"";} _thumbnail_id: '157' _yoast_wpseo_sitemap-prio: '-' _yoast_wpseo_meta-robots-adv: none _yoast_wpseo_sitemap-include: '-' _yoast_wpseo_linkdex: '0' tumblrize_post-type: regular tumblrize_post-group: buonzz.tumblr.com tumblrize_post-id: '25454506214' author: Darwin Biler uri: https://plus.google.com/117859824066667225419 review_rating: '' _wpas_skip_1611607: '1' _wpas_skip_2203490: '1' dsq_thread_id: '2962862408' cleaned: true ---
One of the most frustrating experience in having a new Apple device (iPhone, iPod, iMac) is you have to create an Apple ID for you to use your device in iCloud, iTunes etc., then you will end up iTunes asking for you a credit card info.
You will end up on the above page if you tried creating an account using the "standard way". That is:
1.Open iTunes
2. Go to Store > Create Account
3. A series of page will pop-up, but you will end-up asking for your credit card
Today, I will gonna teach you a tip on how to create an Apple ID without having any credit card/debit card.
To start with go to the iTunes homepage. Look at the right of the page, where you can see the sidebars with headers of "App Store Quick Links", "Top Charts", "Free Apps" etc arranged vertically.
Now on "Free Apps" sidebar. choose any free app in the list.
Click the "Free" button.
That will pop-up a login dialog box asking for Apple ID and password.
Now Click the "Create Apple ID" button
After hitting the button, that should present you a page like this
Now hit "Continue" button, follow the instructions on the page, and you should end up on this page.
Now, among the options of payment method, you will see a card with gray background, with label of "None"
That is the secrect ingredient of our recipe!
Now go on select that option, fill up the form
( Dont forgot to select any value on the Country dropdown )
Now, you should be able to create an Apple ID w/o any card at all!