Skip to content

Branching Ideas #2

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
emschwartz wants to merge 6 commits into
base: main
Choose a base branch
from
Draft

Branching Ideas #2

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
9363916
if / else
emschwartz Jun 26, 2024
6aa01e9
at most m of n
emschwartz Jun 26, 2024
cbe8581
add if then multiple
emschwartz Jun 28, 2024
16d1fb7
pool funds
emschwartz Jun 28, 2024
9b0b09f
fix case where accounts don't have the amount
emschwartz Jun 28, 2024
12c6fc1
remove unused transfer
emschwartz Jun 28, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
28 changes: 28 additions & 0 deletions exercises/at_most_m_of_n.sh
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,28 @@
#!/bin/bash
source ./tools/tb_function.sh

tb "create_accounts id=10000 code=10 ledger=100,
id=10001 code=10 ledger=100,
id=1 code=10 ledger=1 flags=debits_must_not_exceed_credits,
id=2 code=10 ledger=1;"

# Here, we want at most 2 of these transfers to succeed.
# We do that by making each real transfer transfer 1 unit on ledger 1 to an account whose balance is limited to 2.
output=$(tb "create_transfers id=1 debit_account_id=2 credit_account_id=1 amount=2 ledger=1 code=1,

id=100002 debit_account_id=10000 credit_account_id=10001 amount=10 ledger=100 code=10 flags=linked,
id=2 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=1,

id=100003 debit_account_id=10000 credit_account_id=0 amount=100 ledger=100 code=10 flags=linked,
id=3 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=1,

id=100004 debit_account_id=10000 credit_account_id=10001 amount=1000 ledger=100 code=10 flags=linked,
id=4 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=1,

id=100005 debit_account_id=10000 credit_account_id=10001 amount=10000 ledger=100 code=10 flags=linked,
id=5 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=1,

id=6 debit_account_id=2 credit_account_id=1 amount=0 ledger=1 code=10 flags=balancing_credit;")
echo "$output"

tb "lookup_accounts id=1, id=10000;"
21 changes: 21 additions & 0 deletions exercises/if_else.sh
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,21 @@
#!/bin/bash
source ./tools/tb_function.sh

tb "create_accounts id=10000 code=10 ledger=100 flags=debits_must_not_exceed_credits,
id=10001 code=10 ledger=100,
id=1 code=10 ledger=1,
id=2 code=10 ledger=1;"

tb "create_transfers id=100001 debit_account_id=10001 credit_account_id=10000 amount=100 ledger=100 code=10;"

# If amount > 100, the first two transfers will fail.
# If amount <= 100, the first two transfers will succeed and the third and fourth will fail.
# We're deliberately trying to create transfer 100000 in both branches with different codes.
AMOUNT=101
tb "create_transfers id=100002 debit_account_id=10000 credit_account_id=10001 amount=$AMOUNT ledger=100 code=10 flags=linked,
id=100000 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=1,

id=100003 debit_account_id=10000 credit_account_id=10001 amount=50 ledger=100 code=10 flags=linked,
id=100000 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=2;"

tb "lookup_transfers id=100000;"
46 changes: 46 additions & 0 deletions exercises/if_then_multiple.sh
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,46 @@
#!/bin/bash
source ./tools/tb_function.sh

# We can use the technique described in ./if_else.sh to execute a transfer
# if a condition is met. We can use the same technique to execute multiple transfers
# if that condition is met by using linked transfers.

# However, our conditional set of transfers must ALL succeed in order for it to work.
# If one of them might fail, that technique is insufficient.

# We can instead use the technique illustrated here to check a condition and, if it is met,
# execute a set of transfers where the success or failure of one does not affect the others.

tb "create_accounts id=10000 code=10 ledger=100 flags=debits_must_not_exceed_credits,
id=10001 code=10 ledger=100,
id=1 code=10 ledger=1 flags=debits_must_not_exceed_credits,
id=2 code=10 ledger=1;"

tb "create_transfers id=100000 debit_account_id=10001 credit_account_id=10000 amount=100 ledger=100 code=10;"

# If amount > 100, all of the transfers will fail.
# If amount <= 100, the following events will happen:
# - Transfer 11 will succeed and set account 2's net credit balance to be 2.
# - Transfer 100003 will succeed, and transfer 13 will take 1 unit back from account 1 to account 2.
# - Transfer 100004 will fail, along with transfer 14, but this will not affect the others.
# - Transfer 100005 will succeed, and transfer 15 will take 1 unit back from account 1 to account 2.
# - Transfer 100006 and 16 will fail because account 1 no longer has a sufficient balance to transfer 1 unit.

AMOUNT=101 # try changing this to 100 to make the set of transfers succeed
tb "create_transfers id=100001 debit_account_id=10000 credit_account_id=10001 amount=$AMOUNT ledger=100 code=10 flags=linked | pending,
id=100002 pending_id=100001 flags=linked | void_pending_transfer,
id=11 debit_account_id=2 credit_account_id=1 amount=2 ledger=1 code=10,

id=13 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=10 flags=linked,
id=100003 debit_account_id=10000 credit_account_id=10001 amount=50 ledger=100 code=10,

id=14 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=10 flags=linked,
id=100004 debit_account_id=10000 credit_account_id=10001 amount=99999 ledger=100 code=10,

id=15 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=10 flags=linked,
id=100005 debit_account_id=10000 credit_account_id=10001 amount=50 ledger=100 code=10,

id=16 debit_account_id=1 credit_account_id=2 amount=1 ledger=1 code=10 flags=linked,
id=100006 debit_account_id=10000 credit_account_id=10001 amount=50 ledger=100 code=10;"

tb "lookup_transfers id=100003, id=100004, id=100005, id=100006;"
78 changes: 78 additions & 0 deletions exercises/pool_funds.sh
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,78 @@
#!/bin/bash
source ./tools/tb_function.sh

# This example shows how to pool a certain amount from multiple accounts to transfer to a single account.
# Note that it builds on the mechanisms introduced in ./if_then_multiple.sh

OPERATOR_ACCOUNT=10000
POOL_ACCOUNT=10001
CHECK_ACCOUNT=10002
ACCOUNT_1=10003
ACCOUNT_2=10004
TARGET_ACCOUNT=10005
IF_ACCOUNT=10
IF_OPERATOR=11
tb "create_accounts id=$OPERATOR_ACCOUNT code=10 ledger=100,
id=$CHECK_ACCOUNT code=10 ledger=100 flags=credits_must_not_exceed_debits,
id=$POOL_ACCOUNT code=10 ledger=100,
id=$ACCOUNT_1 code=10 ledger=100 flags=debits_must_not_exceed_credits,
id=$ACCOUNT_2 code=10 ledger=100 flags=debits_must_not_exceed_credits,
id=$TARGET_ACCOUNT code=10 ledger=100 flags=debits_must_not_exceed_credits,
id=$IF_ACCOUNT code=10 ledger=1 flags=debits_must_not_exceed_credits,
id=$IF_OPERATOR code=10 ledger=1;"

echo "funding accounts 1 and 2 with 100 units"

# Now, we'll fund Accounts 1 and 2 with 100 units each.
tb "create_transfers id=1000 debit_account_id=$OPERATOR_ACCOUNT credit_account_id=$ACCOUNT_1 amount=100 ledger=100 code=10,
id=1001 debit_account_id=$OPERATOR_ACCOUNT credit_account_id=$ACCOUNT_2 amount=100 ledger=100 code=10;"

# Now, we want to pool funds between ACCOUNT_1 and ACCOUNT_2 to transfer to TARGET_ACCOUNT.
POOL_AMOUNT=250 # Change this to 150 to make the transfers succeed.

echo "pooling funds from accounts 1 and 2 to transfer to target account"

# This looks very complicated, so let's go through each block of transfers.

# The first block checks that the sum of the balances of ACCOUNT_1 and ACCOUNT_2 is greater than or equal to the POOL_AMOUNT.
# If they are, that whole first block of transfers will fail.

# If the first block of transfers fails, the second block of transfers will succeed
# (because the transfer with id=10 intentionally appears in both the first and second blocks -- it will only succeed once).
# This block of transfers transfers 2 units to the IF_ACCOUNT
# AND it *DEBITS* the POOL_ACCOUNT by the POOL_AMOUNT.

# The third and fourth blocks of transfers transfer *EXACTLY* the POOL_AMOUNT from ACCOUNT_1 and ACCOUNT_2 to the POOL_ACCOUNT.
# In each of these blocks, the first transfer (id=11 and id=12) take 1 unit from the IF_ACCOUNT
# (these would fail if the second block of transfers hadn't put 2 units in the IF_ACCOUNT).
# Then, they transfer (id=1009, id=1011) the lesser of the POOL_AMOUNT and the net credit balance of ACCOUNT_1 or ACCOUNT_2 to the POOL_ACCOUNT.
# Then, if the POOL_ACCOUNT now has a credit balance that is *GREATER* than the POOL_AMOUNT they transfer (id=1010, id=1012) the execess back to the account it came from.
# It is important that this last transfer in these blocks is *NOT* linked, because it will fail if the POOL_ACCOUNT's credit balance is less than or equal to the POOL_AMOUNT.

# Finally, the last block of transfers transfers the POOL_AMOUNT from the POOL_ACCOUNT to the TARGET_ACCOUNT
# and resets the POOL_ACCOUNT's net balance back to 0.

output=$(tb "create_transfers id=1002 debit_account_id=$CHECK_ACCOUNT credit_account_id=$OPERATOR_ACCOUNT amount=$((POOL_AMOUNT - 1)) ledger=100 code=10 flags=linked,
id=1003 debit_account_id=$ACCOUNT_1 credit_account_id=$CHECK_ACCOUNT amount=0 ledger=100 code=10 flags=linked | pending | balancing_debit,
id=1004 debit_account_id=$ACCOUNT_2 credit_account_id=$CHECK_ACCOUNT amount=0 ledger=100 code=10 flags=linked | pending | balancing_debit,
id=1005 pending_id=1003 code=10 flags=linked | void_pending_transfer,
id=1006 pending_id=1004 code=10 flags=linked | void_pending_transfer,
id=10 debit_account_id=$IF_OPERATOR credit_account_id=$IF_ACCOUNT amount=2 ledger=1 code=10 flags=linked | pending,
id=11 pending_id=10 code=10 flags=void_pending_transfer,
id=1007 debit_account_id=$OPERATOR_ACCOUNT credit_account_id=$CHECK_ACCOUNT amount=0 ledger=100 code=10 flags=balancing_credit,

id=10 debit_account_id=$IF_OPERATOR credit_account_id=$IF_ACCOUNT amount=2 ledger=1 code=11 flags=linked,
id=1008 debit_account_id=$POOL_ACCOUNT credit_account_id=$OPERATOR_ACCOUNT amount=$POOL_AMOUNT ledger=100 code=10,

id=11 debit_account_id=$IF_ACCOUNT credit_account_id=$IF_OPERATOR amount=1 ledger=1 code=10 flags=linked,
id=1009 debit_account_id=$ACCOUNT_1 credit_account_id=$POOL_ACCOUNT amount=$POOL_AMOUNT ledger=100 code=10 flags=balancing_debit,
id=1010 debit_account_id=$POOL_ACCOUNT credit_account_id=$ACCOUNT_1 amount=0 ledger=100 code=10 flags=balancing_debit,

id=12 debit_account_id=$IF_ACCOUNT credit_account_id=$IF_OPERATOR amount=1 ledger=1 code=10 flags=linked,
id=1011 debit_account_id=$ACCOUNT_2 credit_account_id=$POOL_ACCOUNT amount=$POOL_AMOUNT ledger=100 code=10 flags=balancing_debit,
id=1012 debit_account_id=$POOL_ACCOUNT credit_account_id=$ACCOUNT_2 amount=0 ledger=100 code=10 flags=balancing_debit,

id=1013 debit_account_id=$POOL_ACCOUNT credit_account_id=$TARGET_ACCOUNT amount=$POOL_AMOUNT ledger=100 code=10 flags=balancing_debit;")
echo "$output"

tb "lookup_accounts id=$POOL_ACCOUNT, id=$CHECK_ACCOUNT, id=$ACCOUNT_1, id=$ACCOUNT_2, id=$TARGET_ACCOUNT;"