1. A computer-implemented method for efficiently extracting contents of container files, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising: receiving, at a first stage of a file-archiving system, an unnested container file containing a first constituent file and a second constituent file, wherein: the first constituent file is a nested container file that contains the second constituent file; and the file-archiving system is configured to perform a time-consuming file-indexing operation; enabling high file throughput at the first stage of the file-archiving system by refraining, at the first stage of the file-archiving system, from performing the time-consuming file-indexing operation; enabling a second stage of the file-archiving system to perform the time-consuming file-indexing operation on the second constituent file by creating, at the first stage of the file-archiving system, a content hierarchy for the unnested container file that comprises: metadata of the second constituent file; first hierarchical metadata that indicates that the unnested container file contains the nested container file; and second hierarchical metadata that indicates that the nested container file contains the second constituent file; using, at the second stage of the file-archiving system, the content hierarchy to locate the second constituent file within the nested container file; extracting, at the second stage of the file-archiving system, the second constituent file from the nested container file; performing, at the second stage of the file-archiving system, the time-consuming file-indexing operation on the second constituent file.
1. A computer-implemented method for efficiently extracting contents of container files, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising: receiving, at a first stage of a file-archiving system, an unnested container file containing a first constituent file and a second constituent file, wherein: the first constituent file is a nested container file that contains the second constituent file; and the file-archiving system is configured to perform a time-consuming file-indexing operation; enabling high file throughput at the first stage of the file-archiving system by refraining, at the first stage of the file-archiving system, from performing the time-consuming file-indexing operation; enabling a second stage of the file-archiving system to perform the time-consuming file-indexing operation on the second constituent file by creating, at the first stage of the file-archiving system, a content hierarchy for the unnested container file that comprises: metadata of the second constituent file; first hierarchical metadata that indicates that the unnested container file contains the nested container file; and second hierarchical metadata that indicates that the nested container file contains the second constituent file; using, at the second stage of the file-archiving system, the content hierarchy to locate the second constituent file within the nested container file; extracting, at the second stage of the file-archiving system, the second constituent file from the nested container file; performing, at the second stage of the file-archiving system, the time-consuming file-indexing operation on the second constituent file. 2. The computer-implemented method of claim 1 , wherein: the file-archiving system comprises: at least one computing node that comprises hardware resources that are optimized to parse container-file metadata; at least one additional computing node that comprises additional hardware resources that are optimized to perform the time-consuming file-indexing operation; the first stage of the file-archiving system is performed by the at least one computing node; the second stage of the file-archiving system is performed by the at least one additional computing node.