> For the complete documentation index, see [llms.txt](https://comboox.gitbook.io/whitepaper-en/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://comboox.gitbook.io/whitepaper-en/technical-brochure/key-objects/share-and-sharesrepo.md).
# Share and SharesRepo
## **Function and Usage**
[**SharesRepo**](https://github.com/paul-lee-attorney/comboox/blob/master/contracts/lib/SharesRepo.sol) is the most crucial public library in the system, which is utilized to track the creation, update, transfer and cancellation of shares.
## **Members and Attributes**
The share library consists of two objects: **shares** and **share class**, as well as a "number->object" mapping table composed of these two key objects.
## **Share**
The share consists of two main attributes, **Head** and **Body**. Head mainly records the unchangeable attributes since created, e.g., share number, share class, etc.; Body mainly records the attributes that may change dynamically during the share transaction, e.g., the par value of a share, the paid-in contribution, and clean paid-in contribution.
Share Object Structure
#### Attribute List of Shares
| Attribute | Commercial and Legal Meaning |
| ------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| class | The share class, which can be used to distinguish different financing rounds, different shareholders’ equity, and possibly different voting weights. |
| seqOfShare | Share Sequence Number. |
| preSeq | Sequence number of underlying shares. Practically, underlying shares will be canceled and the identical shares will be issued to the buyer during a share transaction, and the sequence number of the transferred shares will be recorded in preSeq of newly-created shares. |
| issueDate | The date of new share issuance or the delivery date of share transactions. |
| shareholder | The user number of shareholder. |
| priceOfPaid | The unit price of the paid-in contribution, which reflects the paid-in share amount in a share transaction, and reflects the premium of the paid-in share amount of the company in a capital increase transaction. |
| priceOfPar | The unit price of the subscribed contribution, which reflects the unpaid subscribed contribution in a share transaction, and reflects the premium of subscribed and unpaid shares of the company. |
| votingWeight | Voting weight is a percentage. Each subscribed share represents 100 times the total of voting rights. For example, "100" means per dollar of subscribed shares represent one vote; "1800" means per dollar of subscribed shares represent 18 vote. |
| payInDeadline | The deadline of paid-in subscribed contribution. It is a 48-bit timestamp with millisecond precision. |
| par | The subscribed share amount, which may remain some subscribed but unpaid contribution. |
| paid | paid-in share amount is the total amount actually paid. |
| cleanPaid | Clean paid-in contribution, which is the amount without any encumbrances such as pledge and assignments. |
| state | The state of share. |
| para | Pre-set attributes. |
### **Share Class**
**Share Class** is a list of **share numbers** summarized in the **share mapping** by **share class** and the aggregated information for the **contribution amount** in that share class.
Share Class Object Structure
### **Shares repo**
**Shares repo** consists of two mappings, one is a **share mapping** for "share number -> share object" and a **class mapping** for "share class number -> share class object"**.**
Shares repo structure
## **Query API**
The query API well reflects the function and usage of the **shares repo** in the overall system, as shown in the table below.
| API | Function and Usage |
| --------------------- | ----------------------------------------------------------- |
| counterOfShares | Get the current value of the share number counter. |
| counterOfClasses | Get the current value of the share class number counter. |
| isShare | Verify the existence of a specific share number. |
| getShare | Get the share object for the specific number. |
| getQtyOfShares | Get the total number of current share objects. |
| getSeqListOfShares | Get the list of shares sequence numbers. |
| getSharesList | Get a list of all shares objects. |
| getQtyOfSharesInClass | Get the total number of shares in a specific share class. |
| getSeqListOfClass | Get a list of share numbers for a specific share class. |
| getInfoOfClass | Get aggregated information for a specific share class. |
| getSharesOfClass | Get a list of all share objects for a specific share class. |
## Source Code
#### [SharesRepo](https://github.com/paul-lee-attorney/comboox/blob/master/contracts/lib/Checkpoints.sol)